@article { ISI:000226717900001, title = {Influence of PdO content and pathway of its formation on methane combustion activity}, journal = {Catalysis Communications}, volume = {6}, number = {2}, year = {2005}, month = {FEB}, pages = {97-100}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The methane oxidation reaction is known to induce changes in the surface structure and composition of Pd catalysts; making it extremely arduous to relate the methane oxidation activity to specific catalyst properties by conventional methods (continuous flow reactor studies). To circumvent this, methodical pulse reactor studies have been undertaken to obtain correlations between the initial methane combustion activity and the catalyst properties (Pd-0/PdO content and path of PdO formation). While the initial methane combustion activity (at 160-280 degreesC) continuously increased with increasing PdO concentration (0-100\%) in the catalyst, it continuously decreased with increasing Pddegrees content (0-100\%). Controlled studies were undertaken to obtain catalysts with identical PdO content by two pathways: (i) by controlled partial oxidization of Pd-0/Al2O3 and (ii) by controlled partial reduction of PdO/Al2O3. Interestingly, for a given PdO content, the catalysts obtained by partial oxidation of Pd-0/Al2O3 showed a significantly superior performance to the catalyst obtained by partial reduction of PdO/Al2O3 for all the temperatures investigated. These studies unambiguously show that along with the relative concentration of PdO, the PdO formation pathway is also critical in deciding the methane combustion activity of the catalyst. (C) 2004 Elsevier B.V. All rights reserved.

}, keywords = {Methane combustion, Oxidation, partially oxidized Pd-0/Al2O3, partially reduced PdO/Al2O3, Pd-0/Al2O3, PdO/Al2O3, pulse reaction of methane}, issn = {1566-7367}, doi = {10.1016/j.catcom.2004.11.004}, author = {Choudhary, Tushar V. and Banerjee, S. and Choudhary, Vasant R.} } @article { ISI:000231401000008, title = {Influence of silica source in the catalytic activity and heterogenity of mesoporous vanadosilicates}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {239}, number = {1-2}, year = {2005}, month = {SEP}, pages = {57-63}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Vanadium-substituted ordered mesoporous silicates (V-OMS) were synthesized hydrothermally using two common silica sources, viz. fumed silica and tetraethyl orthosilicate, and their surface properties and catalytic activities were evaluated in the liquid phase oxidation of 1-napthol using aqueous H2O2 as an oxidant. The catalysts were characterized by XRD, N-2, adsorption-desorption, DRUV-vis and TPR to evaluate the mesostructural ordering and the local environment of vanadium in the MCM-41 matrix. Characterization data of the fresh calcined catalysts reveal a more ordered hexagonal structure for the V-MCM-41 catalyst prepared by using tetraethyl orthosilicate as the silica source while spent catalyst showed that the material is less stable than the V-MCM-41 catalyst prepared by using fumed silica as the silica source. Further, the observed differences in the selectivity behavior of extracted and calcined forms of both vanadium catalysts shows that the treatment conditions had a decisive role in the formation of extra framework metal species and further in the mesoscopic structural ordering. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {1-napthol, MCM-41, Mesoporous, Oxidation, Vanadium}, issn = {1381-1169}, doi = {10.1016/j.molcata.2005.05.029}, author = {Shylesh, S. and Mirajkar, Subhash P. and Singh, A. P.} } @article { ISI:000232712200011, title = {Synthesis, characterization and catalytic activity of Mn(III)- and Co(II)-salen complexes immobilized mesoporous alumina}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {241}, number = {1-2}, year = {2005}, month = {NOV}, pages = {79-87}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Mn(III) and Co(II)-schiff base complexes were immobilized over mesoporous alumina through the reaction of mesoporous alumina functionalized 3-aminopropyl triethoxy silane (3-APTES) and salicylic aldehyde via schiff base condensation. The surface properties of the functionalized catalysts were analyzed by a series of characterization techniques like elemental analysis, PXRD, FTIR, N(2) adsorption-desorption, TG-DTG, DR UV-vis, XPS, etc. PXRD and adsorption-desorption analysis shows that the mesostructure of alumina remains intact after various modifications, while spectral technique show the successful anchoring of the neat complexes inside the porous alumina support. The catalytic activity of the functionalized metal-salen complexes examined in the liquid phase oxidation of styrene and cyclohexene shows that the functionalized salen complexes are more active and selective than the corresponding neat metal complexes. Further, the catalyst (Mn-S-NH(2)-MA) was recycled three times in the oxidation of styrene and no major change in the conversion and selectivity is observed, which shows that the immobilized metal-salen complexes are stable under the present reaction conditions. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Immobilization, Mesoporous alumina, Oxidation, Schiff base complexes}, issn = {1381-1169}, doi = {10.1016/j.molcata.2005.07.005}, author = {Chaube, V. D. and Shylesh, S. and Singh, A. P.} } @article { ISI:000229488700008, title = {Vapor phase oxidation of 4-fluorotoluene over vanadia-titania catalyst}, journal = {Journal of Molecular Catalysis A - Chemical}, volume = {234}, number = {1-2}, year = {2005}, month = {JUN}, pages = {51-57}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The vapor phase oxidation of 4-fluorotoluene has been carried out over vanadia-titania catalysts with moderate conversion and selectivity for 4-fluorobenzaldehyde. Two series of V2O5/TiO2 catalysts with 1-10 mol\% vanadia were prepared by sol-gel technique using vanadium and titanium peroxide as vanadia and titania precursors respectively and by impregnation technique using vanadium peroxide on anatase titania support. The samples were characterized by X-ray diffraction, NH3-TPD, FT-IR and BET surface area measurements. The XRD of the catalysts prepared by impregnation technique showed retention of the anatase titania whereas the catalysts prepared by sol-gel technique showed the formation of rutile titania with minor amount of anatase phase at lower vanadia content (1-3 \%), which completely transformed into anatase phase at higher vanadia loading. The samples prepared by sol-gel method showed higher acidity and surface area compared to the samples prepared by impregnation. Pyridine adsorption study by FT-IR revealed the presence of Lewis acidity at lower vanadia loading (1-3 \%) and presence of both Lewis as well as Bronsted acidity at higher vanadia loading. The catalytic activity for oxidation of 4-fluorotoluene increased with vanadia loading in the sol-gel catalysts. The catalysts prepared by impregnation technique were found to be less active. However the selectivity for 4-fluorobenzaldehyde decreased with increase in vanadia content. The influence of vanadia loading, reaction temperature and contact time on the catalytic activity for 4-fluorotoluene oxidation has been investigated. The structure of the catalyst and its catalytic activity has been correlated. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Catalyst, fluorotoluene, Oxidation, vanadia-titania, vapor phase}, issn = {1381-1169}, doi = {10.1016/j.molcata.2005.02.020}, author = {Maurya, S. K. and Patil, P. and Shubhangi B. Umbarkar and Gurjar, M. K. and Dongare, Mohan K. and Rudiger, S. and Kemnitz, E.} } @article { ISI:000239671800023, title = {Cobalt-containing hexagonal mesoporous molecular sieves (Co-HMS): Synthesis, characterization and catalytic activity in the oxidation reaction of ethylbenzene}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {255}, number = {1-2}, year = {2006}, month = {AUG}, pages = {123-130}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Cobalt-containing hexagonal mesoporous materials (Co-HMS and Co/HMS) with different cobalt content were synthesized for the first time by direct hydrothermal and post-synthesis (grafting) method. The materials were characterized in detail by X-ray diffraction, BET surface area, N-2 sorption isotherms, SEM, TEM, UV-vis and XPS techniques. Powder X-ray diffraction pattern, N2 adsorption-desorption analysis and TEM analysis show the presence of hexagonal mesoporous structure, having Type W isotherms and reveals the typical wormhole-like morphology. Spectroscopic techniques like UV-vis and XPS reveal cobalt in +2 oxidation state and tetrahedrally coordinated. Liquid phase oxidation of ethylbenzene using TBHP (70 wt\%) as an oxidant shows that the catalysts are highly active, under solvent free conditions as well as under lower cobalt concentrations. Leaching studies performed by hot filtration experiments show that the cobalt catalysts prepared by hydrothermal methods are stable, while the grafted catalysts show the leaching of cobalt under the reaction conditions. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Co-HMS, ethylbenzene, HMS, hydrothermal, Oxidation}, issn = {1381-1169}, doi = {10.1016/j.molcata.2006.03.072}, author = {Bhoware, Shrikant S. and Shylesh, S. and Kamble, K. R. and Singh, A. P.} } @article { ISI:000238491100062, title = {Effect of calcination cycles on the preparation of tin oxide based traditional drug: studies on its formation and characterization}, journal = {Journal of Pharmaceutical and Biomedical Analysis}, volume = {41}, number = {4}, year = {2006}, month = {JUN}, pages = {1473-1478}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The preparation method of metal based Indian traditional drugs involves conversion of a pure metal into its oxide by repeated high temperature calcination cycles. In this work, the effect of number of calcination cycles followed in the preparation of tin oxide based Ayurvedic drug, {\textquoteleft}vanga bhasma{\textquoteright} was studied by a systematic characterization of the drug samples after various calcination stages. It was found that tin was in the form of Sn4+ state and that the formation of SnO2 proceeded step-wise through Sn(OH)(4). (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {calcination cycles, Oxidation, oxidation state of tin, Particle size, tin oxide, vanga bhasma}, issn = {0731-7085}, doi = {10.1016/j.jpba.2006.03.032}, author = {Wadekar, M. P. and Rode, C. V. and Bendale, Y. N. and Patil, K. R. and Gaikwad, A. B. and Prabhune, Asmita} } @article { ISI:000237937900022, title = {Enantioselective synthesis of (-)-cytoxazone and (+)-epi-cytoxazone, novel cytokine modulators via sharpless asymmetric epoxidation and L-proline catalyzed mannich reaction}, journal = {Tetrahedron}, volume = {62}, number = {24}, year = {2006}, month = {JUN}, pages = {5756-5762}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A short and efficient enantioselective synthesis of (-)-cytoxazone and its stereoisomer (+)-epi-cytoxazone, novel cytokine modulators, has been described with good yield and enantioselectivity. Ti-catalyzed Sharpless asymmetric epoxidation of allyl alcohol and L-proline catalyzed three-component Mannich reaction constitute the key steps in introducing stereogenicity into the molecule. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {aminohydroxylation, Asymmetric synthesis, epoxidation, Mannich reaction, Oxidation, Ozonolysis}, issn = {0040-4020}, doi = {10.1016/j.tet.2006.03.079}, author = {Paraskar, Abhimanyu S. and Sudalai, Arumugam} } @article { ISI:000242130100007, title = {Heterogenized vanadyl cations over modified silica surfaces: a comprehensive understanding toward the structural property and catalytic activity difference over mesoporous and amorphous silica supports}, journal = {Journal of Catalysis}, volume = {244}, number = {1}, year = {2006}, month = {NOV}, pages = {52-64}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

Using a postsynthesis grafting method, 3-aminopropyltriethoxysilane (3-APTS) was functionalized over silica gel and mesoporous silica materials like SBA-15 and MCM-41. Vanadyl cations were then immobilized over the functionalized amino groups of the silica samples and used as a catalyst in the liquid-phase oxidation reaction of cyclohexane. Elemental analysis, PXRD, TEM, N-2 adsorption-desorption isotherms, FTIR, C-13 and Si-29 MAS NMR, UV-vis, and EPR techniques were used to characterize the developed materials. Characterization results suggest that the percentage of 3-APTS grafting depends on the number of isolated and genlinal silanol sites of the support material, the solvents used during the grafting reactions, and the sample pretreatment conditions. We found that using toluene as the dispersing medium and Si-MCM-41 as a support provides the maximum amount of amine functionalization, and thereby the highest percentage of vanadium immobilization. Catalytic activity and metal leaching studies show that vanadium-immobilized mesoporous solids are more active and stable than the silica gel-functionalized vanadium catalyst and a framework-substituted V-MCM-41 catalyst. The enhanced activity and stability of the immobilized vanadium catalysts compared with the V-MCM-41 and silica gel samples are attributed to the active metal site isolations, as well as to the spatial restrictions imparted from the concave silica surfaces of the mesoporous solids rather than the convex silica surfaces of the silica gel sample. (c) 2006 Published by Elsevier Inc.

}, keywords = {3-APTS, mesoporous solids, Oxidation, Silica gel, Vanadium}, issn = {0021-9517}, doi = {10.1016/j.jcat.2006.08.002}, author = {Shylesh, S. and Singh, A. R.} } @article { ISI:000241306300020, title = {Oxidation of ethyl benzene and diphenyl methane over ordered mesoporous M-MCM-41 (M = Ti, V, Cr): synthesis, characterization and structure-activity correlations}, journal = {Microporous and Mesoporous Materials}, volume = {95}, number = {1-3}, year = {2006}, month = {OCT}, pages = {154-163}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Transition metals (M = Ti, V, Cr) were incorporated into the MCM-41 framework by surfactant-assisted direct hydrothermal (DHT) methods and were characterized in detail by XRD, N-2 adsorption-desorption, TG-DTG/DTA, SEM/TEM, DR UV-Vis, XPS and EPR. The structural regularity as well as the textural properties of the M-MCM-41 materials was confirmed by XRD, TEM and adsorption-desorption techniques. Nature of metal species and the percentage of framework as well as extra framework metal sites in the MCM-41 matrix are discussed in detail by various spectroscopic techniques. The catalytic activity as well as the selectivity of the M-MCM-41 catalysts were explored in the one-step liquid-phase oxidation reaction of ethyl benzene and diphenyl methane. Reaction data showed that the oxidation activity is more when H2O2 was used an oxidant, acetonitrile as solvent and V-MCM-41 as catalyst. However, the selectivity towards the desired keto derivatives (ethyl benzene to acetophenone and diphenyl methane to benzophenone) follows the order, Ti-MCM-41 \> V-MCM-41 \> Cr-MCM-41. (c) 2006 Elsevier Inc. All rights reserved.

}, keywords = {diphenyl methane, Ethyl benzene, MCM-41, Oxidation}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2006.04.018}, author = {Jha, Ratnesh Kumar and Shylesh, S. and Bhoware, Shrikant S. and Singh, A. P.} } @article { ISI:000244144700016, title = {Chromium-containing small pore mesoporous silicas: synthesis, characterization and catalytic behavior in the liquid phase oxidation of cyclohexane}, journal = {Applied Catalysis A-General}, volume = {318}, year = {2007}, month = {FEB}, pages = {128-136}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Organic-inorganic hybrid mesoporous silica materials containing chromium and various organo trialkoxysilanes (chloropropyl, vinyl, methyl) were prepared by the co-condensation method, in the presence of cetyl trimethyl ammonium surfactants. The hybrid material, containing chromium, retains one X-ray diffractogram (XRD) peak up to a molar ratio of 1: 1 between tetra ethyl orthosilicate (TEOS) and organosilane in the synthesis gel. Small pore mesoporous chromium-silica samples can be prepared from the large pore hybrid mesoporous chromium samples by calcination. By this method, the pore size of the material can be tailored into the supermicroporous region, without changing the chain length of the surfactant used in the assembly process, as judged from the XRD and N-2 sorption isotherms. The shrinkage in pore size is dependent on the nature and percentage of the organic pendant groups, such that the chloro propyl and vinyl pendant mesoporous material show more pore size shrinkage than the smaller methyl pendant units. Because of the tailorable pore size and with better textural characteristics, the chromium samples show better catalytic activity in the aerial oxidation reaction of cyclohexane than the conventional chromium-containing mesoporous material, like Cr-MCM-41, under a solvent free system. Among the porous chromium catalysts, the samples prepared using chloro propyl silane show higher cyclohexane conversion and cyclohexanone selectivity and behave as a true heterogeneous catalyst. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {chromium, Cyclohexane, Oxidation, small pore silicas}, issn = {0926-860X}, doi = {10.1016/j.apcata.2006.10.046}, author = {Shylesh, S. and Samuel, Prinson P. and Singh, A. P.} } @article { ISI:000244983400014, title = {Cross-linking assessment after accelerated ageing of ethylene propylene diene monomer rubber}, journal = {Polymer Degradation and Stability }, volume = {92}, number = {3}, year = {2007}, month = {MAR}, pages = {457-463}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

The ageing of filled and cross-linked ethylene propylene diene elastomer (EPDM) has been studied under accelerated UV irradiation (lambda \>= 290 nm) at 60 degrees C, thermal ageing at 100 degrees C and in nitric acid vapours for different time intervals. Hardness measurements were performed. DSC-thermoporosimetry was used to estimate the mesh size distribution and cross-linking densities for each ageing. The development of functional groups was monitored by ATR spectroscopy. An increase in oxidation with exposure time after the different types of ageing was observed. The thermal stability of EPDM was assessed by TGA and evolved volatile gases were identified using FTIR spectroscopy. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {ageing, EPDM, Oxidation, thermal analysis, thermoporosimetry}, issn = {0141-3910}, doi = {10.1016/j.polymdegradstab.2006.11.013}, author = {Tomer, N. S. and Delor-Jestin, Florence and Singh, R. P. and Lacoste, Jacques} } @article { ISI:000244106200013, title = {One step synthesis of chromium-containing periodic mesoporous organosilicas and their catalytic activity in the oxidation of cyclohexane}, journal = {Microporous and Mesoporous Materials}, volume = {99}, number = {3}, year = {2007}, month = {FEB}, pages = {334-344}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Chromium-containing ethane-bridged hybrid mesoporous materials (Cr-PMO) with uniform hexagonal arrangement were synthesized by two different synthesis routes using 1,2-bis(triethoxysilyl)ethane (BTEE) and tetraethyl orthosilicate (TEOS) as silica sources and alkyltrimethyl ammonium salts (ATMA) as surfactants. Powder X-ray diffraction, TEM, N-2 adsorption-desorption, FT-IR, in situ FT-Raman, UV-ViS, XPS, Si-29 MAS NMR and C-13 CP MAS NMR were used to probe the mesoporous structure and the nature of chromium sites in the hybrid catalyst matrix. PXRD, TEM and N-2 adsorption-desorption analysis showed that the original hexagonal structure of the materials is maintained after chromium substitution, while FT-Raman, UV-Vis and XPS analysis showed that chromium atoms exist in a highly dispersed state. The catalytic performance of the chromium-containing hybrid samples was tested in the liquid-phase oxidation of cyclohexane with aqueous hydrogen peroxide (H2O2) and non-aqueous tert-butylhydroperoxide (TBHP) as oxidants. The hybrid materials exhibited better catalytic activities and were more stable than the conventional Cr-MCM-41 catalyst. The higher catalytic activity of the new chromium-containing molecular sieves is attributed to the improved hydrophobicity of the materials and to the complementary structural features that facilitates the accessibility of cyclohexane to the active framework chromium sites. (c) 2006 Elsevier Inc. All rights reserved.

}, keywords = {Cr-MCM-41, Cr-PMO, Cyclohexane, hybrid mesoporous materials, Oxidation}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2006.09.029}, author = {Shylesh, S. and Srilakshmi, Ch. and Singh, A. P. and Anderson, B. G.} } @article { ISI:000248918000008, title = {Oxidation of benzylic alcohols and sulfides over LaCoO3 and TBHP}, journal = {Arkivoc}, number = {1}, year = {2007}, month = {JAN}, pages = {70-75}, publisher = {ARKAT USA INC}, type = {Article}, address = {C/O ALAN R KATRITZKY, UNIV FLORIDA, DEPT CHEMISTRY, PO BOX 117200, GAINESVILLE, FL 32611 USA}, abstract = {

A simple and efficient methodology has been described for the selective oxidation of secondary benzylic alcohols to the corresponding ketones. In contrast, primary benzylic alcohols afforded dimethyl acetals.

}, keywords = {acetals, benzylic alcohols, Oxidation, perovskite LaCoO3}, issn = {1551-7004}, author = {Patil, Mahesh L. and Maujan, Suleman R. and Borate, Hanumant B. and Uphade, Balu S.} } @article { ISI:000244183400009, title = {[SbW9O33]-based polyoxometalate combined with a phase transfer catalyst: A highly effective catalyst system for selective oxidation of alcohols with H2O2, and spectroscopic investigation}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {262}, number = {1-2}, year = {2007}, month = {FEB}, pages = {52-58}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Na-9[SbW9O33] in conjunction with a phase transfer catalyst, methyltricapryl ammonium chloride, is highly efficient for selective oxidation of variety of alcohols with aq. H2O2 to yield corresponding carbonyls. Most importantly the reactions are carried out in the absence of any organic solvents especially halogenated solvents. In case of allylic alcohols, the catalyst is highly selective for the alcohol oxidation reaction and least selective for epoxidation reaction in the presence of aq. H2O2. IR studies support the formation of W-peroxo intermediate species and also support the stability of the catalyst in the presence of phase transfer compound under the present experimental condition. The catalyst can be reused after careful decomposition of peroxide of the final reaction mixture. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Alcohol, Aq.H2O2, Nag[SbW9O33], Oxidation, Phase transfer catalyst, Polyoxometalate, polyoxotungstate}, issn = {1381-1169}, doi = {10.1016/j.molcata.2006.08.050}, author = {Ingle, Rohit H. and Raj, N. K. Kala and Manikandan, Palanichamy} } @article { ISI:000250026200021, title = {Synthesis of tinidazole by condensation-oxidation sequence using MoO3/SiO2 bifunctional catalyst}, journal = {Catalysis Communications}, volume = {8}, number = {10}, year = {2007}, month = {OCT}, pages = {1550-1555}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Antimicrobial drug, tinidazole has been synthesized by condensation of 2-methyl,5-nitro-imidazole and 2-ethyl-thio-ethanol over MoO3/SiO2 catalyst to obtain 1-(2-ethyl-thio-ethanol)-2-methyl-5-nitro-imidazole which is further oxidized using hydrogen peroxide using the same MoO3/SiO2 catalyst to obtain tinidazole. MoO3/SiO2 catalyst (20\%), synthesized by sol-gel process showed the highest acid strength and was successfully demonstrated to catalyze both condensation and oxidation in the synthesis of tinidazole. Due to the bifunctional activity of the catalyst, the use of acetic acid for condensation step and tungstic acid or ammonium molybdate for oxidation step in the conventional synthesis of tinidazole could be eliminated, thus making it an environmentally benign process. The catalysts could be recycled five times without any appreciable loss in the conversion and selectivity showing the potential for. the use of MoO3/SiO2 as bifunctional catalyst for the production of this industrially important compound. (C) 2007 Elsevier B.V. All rights reserved.

}, keywords = {antimicrobial drug, condensation, MoO3/SiO2, Oxidation, solid acid catalyst, tinidazole}, issn = {1566-7367}, doi = {10.1016/j.catcom.2007.01.001}, author = {Chandorkar, J. G. and Shubhangi B. Umbarkar and Rode, C. V. and Kotwal, V. B. and Dongare, Mohan K.} } @article { ISI:000252529400004, title = {Bridging the gap between micropores and mesopores by the controlled transformation of bifunctional periodic mesoporous silicas}, journal = {Microporous and Mesoporous Materials}, volume = {108}, number = {1-3}, year = {2008}, month = {FEB}, pages = {29-40}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Novel bifunctional periodic mesoporous silicas having high content of organic groups in the pore channels and chromium in the frame wall has been synthesized by direct co-condensation method, using organo trialkoxysilanes (chloro propyl, vinyl, methyl), chromium nitrate and tetraethyl orthosilicate, in presence of cetyltrimethyl ammonium surfactants. The obtained materials show one main peak in the XRD patterns up to a molar ratio of 1: 1 between TEOS and organosilane in the synthesis gel and N-2 adsorption-desorption analysis shows that the mesopore structure remains intact after the surfactant removal process. Among the organosilanes, chloro propyl and vinyl pendant chromium samples shows a shift in the main peak to higher 2-theta values with a corresponding decrease in pore volume and pore diameter, with the percentage of organosilane functionalization. Small-pore silicas and chromium silicas can be prepared from the large pore mesoporous MCM-41, by effectively removing the organic groups by calcination. By this method, the pore size of the material can be tailored into the super-microporous region, without changing the chain length of the surfactant used in the assembly process. The shrinkage in pore size is dependent on the nature and percentage of the organic pendant groups that the chloro propyl and vinyl pendant mesoporous materials show the maximum pore size shrinkage than the small chain length methyl units. Because of the tailorable pore size and with better textural characteristics, chromium-silica materials find applications in the field of shape selective heterogeneous catalysis, as demonstrated in the oxidation reaction of cyclohexane, than the conventional metal-containing mesoporous materials. (c) 2007 Elsevier Inc. All rights reserved.

}, keywords = {bifunctional silicas, chromium, Cyclohexane, MCM-41, Oxidation}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2007.03.039}, author = {Shylesh, S. and Srilakshini, Ch. and Singh, A. P. and Anderson, B. G.} } @article { ISI:000260290500013, title = {Efficient synthesis of antifungal pyrimidines via palladium catalyzed Suzuki/Sonogashira cross-coupling reaction from Biginelli 3,4-dihydropyrimidin-2(1H)-ones}, journal = {Tetrahedron}, volume = {64}, number = {44}, year = {2008}, month = {OCT}, pages = {10214-10223}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

An efficient regioselective approach to the synthesis of tetrasubstituted pyrimidines was developed by sequential functionalization of easily available Biginelli 3,4-dihydropyrimidine-2(1H)-ones via dehydrogenation, chlorination followed by palladium catalyzed C-C Suzuki/Sonogashira coupling reaction. All the synthesized compounds were evaluated in vitro for their antifungal activities against Candida albicans, Cryptococcus neoformans, Benjaminiella poitrasii, Yarrowia lipolytica, and Fusarium oxysporum, and antibacterial activities against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. (c) 2008 Elsevier Ltd. All rights reserved.

}, keywords = {Antifungal activities, Biginelli compounds, chlorination, Oxidation, Pyrimidines, Suzuki coupling}, issn = {0040-4020}, doi = {10.1016/j.tet.2008.08.033}, author = {Gholap, Atul R. and Toti, Kiran S. and Shirazi, Fazal and Deshpande, Mukund V. and Srinivasan, Kumar V.} } @article { ISI:000259845000014, title = {Inorganic-organic hybrid materials based on functionalized silica and carbon: a comprehensive understanding toward the structural property and catalytic activity difference over mesoporous silica and carbon supports}, journal = {Microporous and Mesoporous Materials}, volume = {115}, number = {3}, year = {2008}, month = {NOV}, pages = {345-355}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Inorganic-organic hybrid materials based on functionalized silica and carbon were synthesized by anchoring molybdovanadophosphoric acid (H-5[PMo10V2O40]center dot 32.5H(2)O) onto amine-functionalized SBA-15, ethane-bridged SBA-15 and mesoporous carbon, respectively. Small angle X-ray diffraction, N-2 sorption analysis, HRTEM, SEM, IFT-IR, CP-MAS NMR were used to diagnose the mesoporous structure of inorganic-organic hybrid materials. The structural integrity of molybdovanadophosphoric acid has been found to be retained after immobilization over mesoporous materials. These inorganic-organic hybrid materials were tested in the environmentally friendly oxidation of 2-methylnaphthalene (2MN) with 30\%, aqueous hydrogen peroxide. Molybdovanadophosphoric acid containing mesoporous organosilica hybrid material (ethane-bridged SBA-15) exhibited higher catalytic activities in the oxidation of 2MN to give a clean product 2-methy-1,4-naphthoquinone (menadione vitamin K3 precursor), because of the improved hydrophobicity of the material. The correlation between structural properties and catalytic activities of these hybrid materials has been well addressed in our present studies. (c) 2008 Elsevier Inc. All rights reserved.

}, keywords = {2-Methylnaphthalene, inorganic-organic hybrid materials, mesoporous carbon, mesoporous organosilica, Oxidation}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2008.02.005}, author = {Bordoloi, Ankur and Mathew, Nevin T. and Lefebvre, F. and Halligudi, Shivaraj B.} } @article { ISI:000256043100018, title = {Selective N-oxidation of aromatic amines to nitroso derivatives using a molybdenum acetylide oxo-peroxo complex as catalyst}, journal = {Tetrahedron Letters}, volume = {49}, number = {22}, year = {2008}, month = {MAY}, pages = {3616-3619}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The molybdenum acetylide oxo-peroxo complex obtained in situ by the treatment of the corresponding molybdenum acetylide carbonyl complex, CpMo(CO)(3)(C CPh); Cp = eta(5-)C(5)H(5) with H(2)O(2), has been used as an efficient catalyst for selective N-oxidation of primary amines to nitroso derivatives. Excellent amine conversion (up to 100\%) and very high selectivity for nitroso compounds (99\%) have been obtained using 30\% hydrogen peroxide as an oxidant. The oxo peroxo, Mo(VI) complex has also been found to be very active for the oxidation of various substituted primary aromatic amines with electron donating as well as electron withdrawing substituents on the aromatic ring. (C) 2008 Elsevier Ltd. All rights reserved.

}, keywords = {aromatic amine, Homogenous catalyst, Hydrogen peroxide, Molybdenum complex, nitroso, Oxidation, Oxo-peroxo}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2008.04.005}, author = {Biradar, Ankush V. and Kotbagi, Trupti V. and Dongare, Mohan K. and Shubhangi B. Umbarkar} } @article { ISI:000260447200004, title = {WO3/70\% TBHP/aqueous NaOH: an efficient catalytic combination for the selective oxidation of methylarenes and alkyl aryl ketones to benzoic acids}, journal = {European Journal of Organic Chemistry}, number = {29}, year = {2008}, month = {OCT}, pages = {4877-4880}, publisher = {WILEY-BLACKWELL}, type = {Article}, address = {COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA}, abstract = {

A new solvent-free, reusable catalytic combination consisting Of WO3/70\% TBHP/aqueous NaOH has been described for the direct oxidation of methylarenes and acetophenones to the corresponding benzoic acids in high yields. Alkylarenes are oxidized to the corresponding aromatic ketones or benzylic alcohols depending upon whether NaOH is used or not. ((C) Wiley-VCH Verlag GmbH \& Co. KGaA, 69451 Weinheim, Germany, 2008)

}, keywords = {Arenes, Benzoic acids, Ketones, Oxidation, Tungsten}, issn = {1434-193X}, doi = {10.1002/ejoc.200800664}, author = {Shaikh, Tanveer Mahammad Ali and Sudalai, Arumugam} } @article { ISI:000270665200029, title = {Catalytic aerobic oxidation of cyclohexane and ethyl benzene over chromium-containing mesoporous organosilicas}, journal = {Catalysis Letters}, volume = {132}, number = {3-4}, year = {2009}, month = {OCT}, pages = {492-499}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Chromium-containing ethane-bridged hybrid periodic mesoporous organosilicas (Cr-PMO) were synthesized using 1,2-bis(triethoxysilyl) ethane (BTEE) and tetraethyl orthosilicate (TEOS) as silica sources and alkyltrimethyl ammonium salts as surfactants by two different synthesis routes. PXRD and N(2) adsorption-desorption analysis shows that the original structure of the materials is maintained after chromium substitution while spectroscopic study proves the incorporation of chromium in the frame wall positions and show the existence of Cr(2)O(3) species in the mixed silica source (BTEE-TEOS) synthesized chromium samples. The catalytic activity of the newly developed chromium samples was evaluated in the liquid phase oxidation of cyclohexane and ethylbenzene using air as an oxidant. Further, the Cr-PMO samples exhibited better cyclohexane conversion and cyclohexanone selectivity than the conventional Cr-MCM-41 and other metal-containing MCM-41 samples. The exceptional activity of the new chromium-containing molecular sieves is attributed to the hydrophobicity of the materials and to the complementary structural features that facilitates the accessibility of substrate to the active framework chromium sites.

}, keywords = {Cr-MCM-41, Cyclohexane, Ethyl benzene, Organosilicas, Oxidation}, issn = {1011-372X}, doi = {10.1007/s10562-009-0121-x}, author = {Singh, A. P. and Torita, N. and Shylesh, S. and Iwasa, N. and Arai, M.} } @article { ISI:000271756700023, title = {Electronic decoupling of surface layers from bulk and its influence in oxidation catalysis: a molecular beam study}, journal = {Applied Surface Science}, volume = {256}, number = {2}, year = {2009}, note = {2nd International Conference on Physics at Surfaces and Interfaces (PSI2009), Puri, INDIA, FEB 23-27, 2009}, month = {OCT}, pages = {443-448}, publisher = {Inst Phys; Indian Assoc Cutivat Sci}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Interactions between oxygen and Pd-surfaces have important implications, especially towards oxidation reactions, and influence of subsurface oxygen to oxidation reactions is the focus of the present study. In our efforts to understand the above aspects, CO oxidation reactions have been carried out with mixed molecular beam (MB), consisting CO and O(2), on Pd(1 1 1) surfaces under a wide variety of conditions (T = 400-900 K, CO: O(2) = 7: 1 to 1: 10). A new aspect of the above reaction observed in the transient kinetics regime is the evidence for oxygen diffusion into Pd subsurface layers, and its significant influence towards CO oxidation at high temperatures (\>= 600 K). Interesting information derived from the above studies is the necessity to fill up the subsurface layers with oxygen atoms to a threshold coverage (theta(O-sub)), above which the reactive CO adsorption occurs on the surface and simultaneous CO(2) production begins. There is also a significant time delay (G) observed between the onset of oxygen adsorption and CO adsorption (and CO(2) production). Above studies suggest an electronic decoupling of oxygen covered surface and subsurface layers, which is slightly oxidized, from the metallic bulk, which induces CO adsorption at high temperatures and simultaneous oxidation to CO(2). (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Electronic decoupling, heterogeneous catalysis, molecular beam, Oxidation, Pd(111), Subsurface diffusion}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2009.06.107}, author = {Thirunavukkarasu, Kandasamy and Nagarajan, Sankaranarayanan and Gopinath, Chinnakonda S.} } @article { ISI:000262582400008, title = {Kinetic evidence for the influence of subsurface oxygen on palladium surfaces towards CO oxidation at high temperatures}, journal = {Chemistry-an Asian Journal}, volume = {4}, number = {1}, year = {2009}, month = {OCT}, pages = {74-80}, publisher = {WILEY-V C H VERLAG GMBH}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

Transient state kinetics of the catalytic oxidation of CO with 0, on Pd-surfaces has been measured under isothermal conditions by using a molecular beam approach. Systematic studies were carried out as a function of reaction temperature and CO+O(2) composition. With sufficient kinetic evidence, we have demonstrated the positive influence of subsurface oxygen towards CO-adsorption and oxidation to CO, at high temperatures (600-900 K) on Pd-surfaces, and the likely electronic nature of the surface changes with oxygen in the subsurface. These studies also provide a direct proof for CO-adsorption with a significantly reactive sticking coefficient at high temperatures on Pd-surfaces exhibiting a significant subsurface O-coverage.

}, keywords = {Adsorption, kinetics, Oxidation, Palladium, surface analysis}, issn = {1861-4728}, doi = {10.1002/asia.200800278}, author = {Gopinath, Chinnakonda S. and Thirunavukkarasu, Kandasamy and Nagarajan, Sankaranarayanan} } @article { ISI:000268500500025, title = {Magnesium oxide supported nano-gold: a highly active catalyst for solvent-free oxidation of benzyl alcohol to benzaldehyde by TBHP}, journal = {Catalysis Communications}, volume = {10}, number = {13}, year = {2009}, month = {JUL}, pages = {1738-1742}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Nano-size gold particles deposited on MgO by the homogeneous deposition- precipitation showed very high catalytic activity with nearly 100\% conversion of benzyl alcohol in a short reaction period (0.5 h) and more over showed excellent reusability in the process. Influence of the catalyst support (MgO, CaO, BaO, SrO, Al(2)O(3), Ga(2)O(3) and In(2)O(3)), method of gold deposition, Au loading and catalyst calcination temperature and also that of the reaction conditions (viz. reaction time and temperature) on the benzyl alcohol to benzaldehyde oxidation have been thoroughly investigated. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Alkaline earth oxides, Benzaldehyde, Benzyl alcohol, Gr.IIIa metal oxides, Oxidation}, issn = {1566-7367}, doi = {10.1016/j.catcom.2009.05.020}, author = {Choudhary, Vasant R. and Dumbre, Deepa K.} } @article { ISI:000266188300010, title = {Selective oxidation of aromatic primary alcohols to aldehydes using molybdenum acetylide oxo-peroxo complex as catalyst}, journal = {Tetrahedron Letters}, volume = {50}, number = {24}, year = {2009}, month = {JUN}, pages = {2885-2888}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Selective oxidation of various aromatic alcohols to aldehydes has been carried out with very high conversion (90\%) and selectivity (90\%) for aldehydes using cyclopentadienyl molybdenum acetylide complex, CpMo(CO)(3)(C CPh) (1) as catalyst and hydrogen peroxide as environmentally benign oxidant, Water-soluble Mo acetylide oxo-peroxo species is formed in situ after reaction of I with aqueous hydrogen peroxide during the Course of reaction as catalytically active species. Interestingly even though the catalyst is homogeneous it Could be recycled very easily by separating the products in organic phase and catalyst in aqueous phase using separating funnel. Even after five recycles no appreciable loss in alcohol conversion and aldehyde selectivity was observed. (C) 2009 Elsevier Ltd. All rights reserved.

}, keywords = {Homogenous catalyst, Hydrogen peroxide, Molybdenum complex, Oxidation, Oxo-peroxo, Primary aromatic alcohol}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2009.03.178}, author = {Biradar, Ankush V. and Dongare, Mohan K. and Shubhangi B. Umbarkar} } @article { ISI:000269259100007, title = {Supported nano-gold catalysts for epoxidation of styrene and oxidation of benzyl alcohol to benzaldehyde}, journal = {Topics in Catalysis}, volume = {52}, number = {12}, year = {2009}, month = {NOV}, pages = {1677-1687}, publisher = {SPRINGER/PLENUM PUBLISHERS}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Nano-gold particles supported on different alkaline earth oxides (viz. MgO, CaO, BaO and SrO), Gr. IIIa metal oxides (viz. Al(2)O(3), Ga(2)O(3), In(2)O(3) and Tl(2)O(3)), transition metal oxides (viz. TiO(2), Cr(2)O(3), MnO(2), Fe(2)O(3), CoO(x), NiO, CuO, ZnO, Y(2)O(3) and ZrO(2)), rare earth metal oxides (viz. La(2)O(3), Ce(2)O(3), Nd(2)O(3), Sm(2)O(3), Eu(2)O(3), Tb(2)O(3), Er(2)O(3) and Yb(2)O(3)) and U(3)O(8) [all prepared by depositing gold on corresponding metal oxide support by deposition precipitation (DP) and/or homogeneous deposition precipitation (HDP) method] were evaluated for their catalytic performance in the liquid phase epoxidation of styrene by tert-butyl hydroperoxide (TBHP) to styrene oxide and also in the solvent-free benzyl alcohol-to-benzaldehyde oxidation (by molecular oxygen or TBHP) reactions. For the epoxidation, the catalytic performance (styrene oxide yield) of the most promising nano-gold catalysts prepared by the HDP method was in the following order: Au/MgO \> Au/Tl(2)O(3) \> Au/Yb(2)O(3) \> Au/Tb(2)O(3) \> Au/CaO (or TiO(2)). However, for the oxidation of benzyl alcohol to benzaldehyde by molecular oxygen, the order of choice for the most promising catalysts (based on benzaldehyde yield) was Au/U(3)O(8) \> Au/Al(2)O(3) \> Au/ZrO(2) \> Au/MgO. Whereas, when TBHP was used as an oxidizing agent for the benzyl alcohol oxidation, the order of choice for the most promising catalysts was Au/U(3)O(8) \> Au/MgO \> Au/TiO(2) \> Au/ZrO(2) \> Au/Al(2)O(3). The catalytic performance of a particular supported nano-gold catalyst was thus found to depend on the reaction catalysed by them. Moreover, it is strongly influenced by a number of catalyst parameters, such as the metal oxide support, the method of gold depositon on the support, the gold loading and also on the catalyst calcination temperature. Nano-gold particles-support interactions seem to play an important role in controlling the deposition of gold ( amount of gold deposited and size and morphology of gold particles), formation of different surface gold species (Au(0), Au(1+) and Au(3+)) and electronic properties of gold particles and, consequently, control the catalytic performance (both the activity and selectivity) of the supported nano-gold catalysts in the reactions. The nano-gold catalysts prepared by the HDP method showed much better catalytic performance than those prepared by the DP, coprecipitation or impregnation method; in general, the HDP method provided supported gold catalysts with much higher gold loading and/or smaller size gold particles than that achieved by the DP and other methods.

}, keywords = {Benzaldehyde, Benzyl alcohol, epoxidation, Metal oxide supports, Nano-gold catalysts, Oxidation, styrene, Styrene oxide}, issn = {1022-5528}, doi = {10.1007/s11244-009-9306-1}, author = {Choudhary, Vasant R. and Dumbre, Deepa K.} } @article { ISI:000276963200003, title = {Novel synthesis and characterization of titanium superoxide and its application in organic oxidative processes}, journal = {Catalysis Surveys from Asia}, volume = {14}, number = {1}, year = {2010}, month = {MAR}, pages = {21-32}, publisher = {SPRINGER/PLENUM PUBLISHERS}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

A novel, exceptionally stable titanium superoxide radical ion was prepared and its structure determined by FTIR, ESR, Raman spectroscopy, X-ray diffraction, thermogravimetric/differential thermal analysis and elemental analysis. This heterogeneous catalyst has been found to be effective for the selective oxidation of aromatic amines and phenols to the corresponding nitro aromatics and p-quinones, respectively. In addition, this non-toxic, inexpensive and reusable catalyst has also been used in aminobromination of olefins, which proceed to give the 1, 2-bromoaminated anti-Markovnikov product. A brief account of these results is summarized in this review.

}, keywords = {Amino Bromination, Anti-Markovnikov, heterogeneous catalyst, Oxidation, Titanium superoxide}, issn = {1571-1013}, doi = {10.1007/s10563-010-9085-5}, author = {Reddy, R. Santhosh and Shaikh, Tanveer Mahamadali and Rawat, Varun and Karabal, Pratibha U. and Dewkar, Gajanan and Suryavanshi, Gurunath and Sudalai, Arumugam} } @article { ISI:000288074100009, title = {Stereoselective synthesis of (-)-galantinic acid}, journal = {Synthesis-Stuttgart}, number = {6}, year = {2011}, month = {MAR}, pages = {901-904}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

An efficient and highly concise synthesis of (-)-galantinic acid has been achieved using an asymmetric allylation reaction of Garner{\textquoteright}s aldehyde.

}, keywords = {Amino alcohol, Chiral pool, iterative asymmetric allylation, Oxidation, stereoselective synthesis}, issn = {0039-7881}, doi = {10.1055/s-0030-1258431}, author = {Dubey, Abhishek and Harbindu, Anand and Kumar, Pradeep} } @article { ISI:000309370500010, title = {Reactions in supercritical carbon dioxide}, journal = {Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical \& Analytical Chemistry}, volume = {51}, number = {9-10, SI}, year = {2012}, month = {SEP}, pages = {1298-1305}, publisher = {NATL INST SCIENCE COMMUNICATION-NISCAIR}, address = {DR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIA}, abstract = {

Use of conventional organic solvents often leads to the formation of hazardous waste, the disposal of which is a matter of environmental concern. Carbon dioxide is considered to be a green reaction medium and a good replacement for conventional organic solvents as it is benign and leads to elimination/reduction of hazardous wastes. Use of CO2 at near/above critical conditions has several additional advantages as the reactions can be pressure-tuned to eliminate transport resistance, increase solvent power and heat capacity. Hence, there has been considerable interest in the use of supercritical carbon dioxide as either a replacement of conventional organic solvent or as a co-solvent in reactions. Herein, recent developmenst in this area during the last decade is reviewed, specifically in gas-liquid (organic hydrogenation, hydroformylation and oxidation) and liquid-liquid (carbon-carbon coupling, alkylation, acetylation, esterification) reactions.

}, keywords = {Alkylation, Carbon dioxide, Hydroformylation, Hydrogenation, Oxidation, Supercritical carbon dioxide}, issn = {0376-4710}, author = {Mayadevi, S.} } @article { ISI:000308345800010, title = {Solvent-free oxidation of aldehydes to acids by TBHP using environmental-friendly -exchanged Mg-Al hydrotalcite catalyst}, journal = {Journal of Chemical Sciences}, volume = {124}, number = {4}, year = {2012}, month = {JUL}, pages = {835-839}, publisher = {INDIAN ACAD SCIENCES}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

A number of hydrotalcite (Mg-Al, Mn-Al, Co-Al, Ni-Al, Mg-Fe, Mg-Cr and Cu-Al) catalysts, with or without MnO-exchange, were evaluated for their performance in the solvent-free oxidation of benzaldehyde to benzoic acid by tert-butyl hydroperoxide under reflux in the absence of any solvent. The MnO-exchanged Mg-Al-hydrotalcite (Mg/Al = 10) showed high activity in the oxidation of different aromatic and aliphatic aldehydes to their corresponding acids and also showed excellent reusability in the oxidation process which is environmental-friendly.

}, keywords = {acid, Aldehyde, MnO4-1-exchanged Mg-Al-hydrotalcite catalyst, Oxidation, TBHP}, issn = {0974-3626}, doi = {10.1007/s12039-012-0268-7}, author = {Choudhary, Vasant R. and Dumbre, Deepa K. and Narkhede, Vijay S.} } @article { ISI:000307308000020, title = {Transesterification of diethyl oxalate with phenol over sol-gel MoO3/TiO2 catalysts}, journal = {Chemsuschem}, volume = {5}, number = {8}, year = {2012}, month = {JUL}, pages = {1467-1473}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The transesterification of diethyl oxalate (DEO) with phenol to form diphenyl oxalate (DPO) has been carried out in the liquid phase over very efficient MoO3/TiO2 solid-acid solgel catalysts. A selectivity of 100?\% with a remarkable maximum yield of 88?\% were obtained, which opens the route to downstream phosgene-free processes for the synthesis of polycarbonates. Interpretation of the results of various acidity measurements (NH3 and pyridine desorption, methanol oxidation as a probe reaction) allowed us to identify the catalytic sites as Lewis acid sites.

}, keywords = {heterogeneous catalysis, Lewis acids, Oxidation, sol-gel processes, transesterification}, issn = {1864-5631}, doi = {10.1002/cssc.201100802}, author = {Kotbagi, Trupti and Duy Luan Nguyen and Lancelot, Christine and Lamonier, Carole and Thavornprasert, Kaew-Arpha and Zhu Wenli and Capron, Mickael and Jalowiecki-Duhamel, Louise and Shubhangi B. Umbarkar and Dongare, Mohan K. and Dumeignil, Franck} } @article { ISI:000344470100036, title = {Molybdenum(VI) dioxo complexes for the epoxidation of allylic alcohols and olefins}, journal = {Journal of Organometallic Chemistry}, volume = {772}, year = {2014}, month = {DEC}, pages = {271-279}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Several molybdenum(VI) dioxo complexes have been investigated as catalyst precursors for allylic alcohol epoxidation using mainly hydrogen peroxide as oxidant. All catalysts proved to be efficient and selective for the epoxidation of allylic alcohols provided the olefins were rather electron rich. Indeed, electron poor substrates could be converted selectively into the corresponding unsaturated aldehydes. A chiral dioxomolybdenum complex based on an optically pure tridentate Schiff base ligand was synthesized and characterized. Though that complex provided an efficient epoxidation catalyst for allylic alcohols and olefins, no chiral induction was observed. During the X-ray diffraction analysis, the cooling at 100 K led to the appearance of super-lattice reflections on diffraction patterns reflecting an ordering of the structure. Instead of one organometallic species observed at 298 K, three similar complexes of the same molecular structure could be observed in the asymmetric unit at 100 K. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Allylic alcohol, epoxidation, Molybdenum, Oxidation, Peroxide}, issn = {0022-328X}, doi = {10.1016/j.jorganchem.2014.09.029}, author = {Pandhare, Swati L. and Jadhao, Rajesh R. and Puranik, Vedavati G. and Joshi, Pranaya V. and Capet, Frederic and Dongare, Mohan K. and Shubhangi B. Umbarkar and Michon, Christophe and Agbossou-Niedercorn, Francine} } @article { ISI:000344330800015, title = {Role of nanointerfaces in Cu- and Cu plus Au-based near-ambient-temperature CO oxidation catalysts}, journal = {ChemCatChem}, volume = {6}, number = {11}, year = {2014}, month = {NOV}, pages = {3116-3124}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Disordered mesoporous Cu-doped ceria-zirconia (Cu0.1Ce0.85Zr0.05O2), and gold deposited (Au/Cu0.1Ce0.85Zr0.05O2) catalysts were synthesized and evaluated for CO oxidation. Onset of CO oxidation activity, and 50\% (100\%) CO2 formation occurs at room temperature (RT), and 77 (120)degrees C, respectively, with Cu0.1Ce0.85Zr0.05O2. A small amount of gold on Cu0.1Ce0.85Zr0.05O2 induces the sustainable oxidation catalysis around RT. Onset of copper reduction temperature decreases from 110 degrees C on Cu0.1Ce0.85Zr0.05O2 to 48 degrees C with Au/Cu0.1Ce0.85Zr0.05O2, highlighting the direct interaction between Cu and Au through a Cu-Au interface. Au particles with a (00 1) facet deposit on an oxygen-deficient site of (111) facet of CeO2-ZrO2. Any decrease in surface Cu-content with increasing Au-content further supports the Au-Cu-Ce/Zr interface interactions. Nanointerfaces of Au clusters on Cu next to oxygen-deficient sites of CeO2-ZrO2 facilitate all the elementary steps of the CO + O-2 reaction to occur in close proximity at ambient conditions.

}, keywords = {carbon monoxide, Gold, heterogeneous catalysis, Oxidation, redox}, issn = {1867-3880}, doi = {10.1002/cctc.201402581}, author = {Gnanakumar, Edwin S. and Naik, Jarpla Madhusudhan and Manikandan, Marimuthu and Raja, Thirumalaiswamy and Gopinath, Chinnakonda S.} } @article { ISI:000337551800010, title = {Solid base supported metal catalysts for the oxidation and hydrogenation of sugars}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {388}, number = {SI}, year = {2014}, month = {JUL}, pages = {90-99}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Pt impregnated on gamma-Al2O3 (acidic support) and hydrotalcite (basic support) catalysts were synthesized, characterized and used in the oxidation and hydrogenation reactions of C5 and C6 sugars. In the absence of homogeneous base, 83\% yield for gluconic acid; an oxidation product of glucose can be achieved over Pt/hydrotalcite (HT) catalyst at 50 degrees C under atmospheric oxygen pressure. Similarly, 57\% yield for xylonic acid, an oxidation product of xylose is also possible over Pt/HT catalyst. Hydrogenation of glucose conducted using Pt/gamma-Al2O3 + HT catalytic system showed 68\% sugar alcohols (sorbitol + mannitol) formation. The 82\% yield for C5 sugar alcohols (xylitol + arabitol) was obtained by subjecting xylose to hydrogenation over Pt/gamma-Al2O3 + HT at 60 degrees C. UV analysis helped to establish the fact that under alkaline conditions sugars prefer to remain in open chain form in the solution and thus exposes -CHO group which further undergoes oxidation and hydrogenation reactions to yield acids and alcohols. (c) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Hydrogenation, Oxidation, Solid base, Sugars, Supported metal catalysts}, issn = {1381-1169}, doi = {10.1016/j.molcata.2013.09.014}, author = {Tathod, Anup and Kane, Tanushree and Sanil, E. S. and Dhepe, Paresh Laxmikant} } @article { ISI:000339378200013, title = {Synthesis of 2,5-furandicarboxylic acid by the aerobic oxidation of 5-hydroxymethyl furfural over supported metal catalysts}, journal = {Reaction Kinetics Mechanisms and Catalysis}, volume = {112}, number = {1}, year = {2014}, month = {JUN}, pages = {173-187}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

Supported Pt catalysts are synthesized, characterized and are used in the liquid phase air oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). Under the optimum reaction conditions of a stepwise increase in the reaction temperature (75 and 140 degrees C for 12 h each), we achieved as high as 96 \% FDCA yield in presence of 1 bar oxygen pressure over Pt/c-Al2O3. It is shown that as the oxygen pressure increases (1-10 bar), the FDCA yields decrease, since at higher partial pressure of oxygen, overoxidation reactions of substrate and product(s) are possible. It is interesting to note that even with air as an oxidant, we obtained similar yields of FDCA as that with oxygen. Moreover, the effects of base (weak or strong), its concentration (equimolar or excess) were studied in detail. It is important to increase the reaction temperature in a stepwise manner to achieve higher yields of FDCA since at higher temperatures HMF undergoes self-degradation and thus the yields of FDCA decrease. The self-degradation of HMF is also proved by undertaking the reaction under nitrogen environment. The study on the effect of substrate-to-catalyst ratio is done to improve up on the economics of overall process. The effect of supports (reducible and non-reducible) and their oxygen storage capacity is discussed and is proposed to be one of the factors to change the course of reaction. Furthermore, we have shown that FDCA formed in the reaction can be successfully isolated (91 \%, isolated yield) in the pure form and its purity is confirmed by NMR, melting point, and elemental analysis. The catalysts were characterized with X-ray powder diffraction, transmission electron microscopy and inductively coupled plasma-optical emission spectroscopy techniques.

}, keywords = {Biomass, FDCA, green chemistry, heterogeneous catalyst, HMF, Impregnation, Oxidation}, issn = {1878-5190}, doi = {10.1007/s11144-014-0689-z}, author = {Sahu, Ramakanta and Dhepe, Paresh Laxmikant} } @article { ISI:000352488300022, title = {Activity enhancement upon the incorporation of titanium: au@ti-sio2 core-shell nanocatalysts for the CO oxidation reaction}, journal = {ChemCatChem}, volume = {7}, number = {7}, year = {2015}, month = {APR}, pages = {1222-1230}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The encapsulation of gold nanoparticles 8-12nm in size within a porous Ti-SiO2 shell to form a core-shell nanoarchitecture was investigated, and the catalytic activity of the resulting structure was probed. Detailed characterization of the synthesized materials shows that the core-shell morphology is lost beyond a certain amount of incorporated titanium, and results in normal gold-supported Ti-SiO2. The material has a high surface area (913m(2)g(-1)) and high porosity, both of which make it an excellent choice for catalytic applications. With the optimum amount of incorporated Ti, the core-shell catalyst shows excellent room-temperature CO oxidation activity over several cycles with retention of its morphology at higher temperatures.

}, keywords = {core-shell structures, gold nanoparticles, Oxidation, Ti-SiO2}, issn = {1867-3880}, doi = {10.1002/cctc.201402954}, author = {Sekhar, Anandakumari C. Sunil and Kottavarithottil Ziyad and Soni, Yogita and Vinod, Chathakudath P.} } @article { ISI:000366429100003, title = {Breaking and making of rings: a method for the preparation of 4-quinolone-3-carboxylic acid amides and the expensive drug ivacaftor}, journal = {European Journal of Organic Chemistry}, number = {34}, year = {2015}, month = {DEC}, pages = {7433-7437}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

A simple and convenient method to access 4-quinolone-3-carboxylic acid amides from indole-3-acetic acid amides through one-pot oxidative cleavage of the indole ring followed by condensation (Witkop-Winterfeldt type oxidation) was explored. The scope of the method was confirmed with more than 20 examples and was successfully applied to the synthesis of the drug Ivacaftor, the most expensive drug on the market.

}, keywords = {Amides, Drug design, Fused-ring systems, Oxidation, Ozonolysis}, issn = {1434-193X}, doi = {10.1002/ejoc.201501048}, author = {Vasudevan, N. and Jachak, Gorakhnath R. and Reddy, D. Srinivasa} } @article { ISI:000349917900007, title = {Can we shift and/or broaden the catalysis regime towards ambient temperature?}, journal = {ChemCatChem}, volume = {7}, number = {4}, year = {2015}, month = {FEB}, pages = {588-594}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

An attempt was made to shift the temperature regime of oxidation catalysis towards ambient temperatures by employing surface modification (SM) as a handle. Systematic SM of Pd(111) was performed by O-atom diffusion into the subsurfaces. Virgin and modified Pd(111) catalysts were evaluated for CO oxidation. Typical CO poisoning observed on virgin surfaces was partially lifted, and ambient CO oxidation was observed on the modified surfaces. CO oxidation was followed by the molecular beam method and near-ambient pressure (NAP) photoelectron spectroscopy under different pressure regimes. UV valence band spectral analysis of the SM and the CO+O-2 reaction on modified Pd(111) surfaces under NAP conditions demonstrated changes in the electronic structures of the surfaces with a change in surface potential by 0.35eV and directly probed CO2 formation under the reaction conditions. Supported metal catalysts may be subjected to SM and evaluated for a shift in the catalysis regime for many different reactions.

}, keywords = {heterogeneous catalysis, Oxidation, photoelectron spectroscopy, surface chemistry, surface modification}, issn = {1867-3880}, doi = {10.1002/cctc.201402979}, author = {Gopinath, Chinnakonda S. and Roy, Kanak and Nagarajan, Sankaranarayanan} } @article { ISI:000354213400020, title = {Modular synthesis of dihydroxyacetone monoalkyl ethers and isosteric 1-hydroxy-2-alkanones}, journal = {European Journal of Organic Chemistry}, number = {13}, year = {2015}, month = {MAY}, pages = {2960-2964}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Straightforward methods for the efficient, systematic preparation of libraries of the title compound classes have been evaluated. A general and efficient modular route to dihydroxyacetone monoethers was developed based on trityl glycidol, which, through epoxide opening, oxidation, and deprotection, provided variously alkylated ethers by three routine operations in good overall yields (eight examples, 24-59\%). The preparation of structurally related 1-hydroxyalkanones depends on the availability of the most economic starting materials and on their physicochemical properties. Thus, the most practical one-step approaches consisted of the sec-selective oxidation of short-chain 1,2-diols (\<= C-6) using NaOCl, and the direct ketohydroxylation of 1-alkenes (\>= C-6) using buffered stoichiometric KMnO4 or catalytic RuO4 with reoxidation by oxone, for which mostly good overall yields were achieved on a multigram scale (nine examples, 15-78\%).

}, keywords = {Alkylation, Hydroxylation, Ketones, Oxidation, Oxygenation, Regioselectivity, synthetic methods}, issn = {1434-193X}, doi = {10.1002/ejoc.201403695}, author = {Gueclue, Deniz and Rale, Madhura and Fessner, Wolf-Dieter} } @article { ISI:000367722500058, title = {N-Heterocyclic carbene catalyzed oxidative coupling of alkenes/alpha-bromoacetophenones with aldehydes: a facile entry to alpha,beta-epoxy ketones}, journal = {Angewandte Chemie-International Edition}, volume = {54}, number = {47}, year = {2015}, month = {NOV}, pages = {14150-14153}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

{A novel, N-heterocyclic carbene (NHC) catalyzed direct oxidative coupling of styrenes with aldehydes has been described for the synthesis of alpha,beta-epoxy ketones in good yields. This unprecedented regioselective oxidative coupling employs NBS/DBU/DMSO (DBU = 1,8-diazabicyclo [5.4. 0] undec-7-ene

}, keywords = {aldehydes, epoxidation, N-heterocyclic carbenes, Oxidation, synthetic methods}, issn = {1433-7851}, doi = {10.1002/anie.201507363}, author = {Reddi, Rambabu N. and Prasad, Pragati K. and Sudalai, Arumugam} } @article { ISI:000352508300032, title = {Reactivity and operational stability of N-Tailed TAMLs through kinetic studies of the catalyzed oxidation of orange II by H2O2: synthesis and x-ray structure of an N-Phenyl TAML}, journal = {Chemistry A-European Journal}, volume = {21}, number = {16}, year = {2015}, month = {APR}, pages = {6226-6233}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

{The catalytic activity of the N-tailed (biuret) TAML (tetraamido macrocyclic ligand) activators [Fe{4-XC6H3-1,2-(NCOCMe2NCO)(2)NR}Cl](2-) (3; N atoms in boldface are coordinated to the central iron atom; the same nomenclature is used in for compounds 1 and 2 below), [X

}, keywords = {Hydrogen peroxide, iron, kinetics, Oxidation, reaction mechanisms}, issn = {0947-6539}, doi = {10.1002/chem.201406061}, author = {Warner, Genoa R. and Mills, Matthew R. and Enslin, Clarissa and Pattanayak, Shantanu and Panda, Chakadola and Panda, Tamas Kumar and Sen Gupta, Sayam and Ryabov, Alexander D. and Collins, Terrence J.} } @article { ISI:000357617800013, title = {Reduced graphene oxide composite with oxidizable manganese/cobalt mixed oxide for p-cresol oxidation by using molecular oxygen}, journal = {ChemPlusChem}, volume = {80}, number = {7}, year = {2015}, month = {JUL}, pages = {1164-1169}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

A composite of graphene oxide (GO) with mixed oxide (MnCo) was prepared by using a solvothermal method. During the synthesis, both the reduction of GO and growth of metal oxides took place simultaneously. The as-prepared composite material was highly selective for the liquid-phase oxidation of p-cresol to form p-hydroxybenzaldehyde in 71\% yield within 1h. The composite material was characterised by SEM, X-ray photoelectron spectroscopy, high-resolution TEM and cyclic voltammetry (CV). A CV study revealed that the increase in the redox potential of the mixed oxide after being supported on GO, led to its higher activity of the catalyst for the oxidation reaction. The stability of the catalyst under the reaction conditions was studied by its successful reuse in three cycles.

}, keywords = {cyclic voltammetry, graphene, Oxidation, supported catalysts, transition metals}, issn = {2192-6506}, doi = {10.1002/cplu.201500053}, author = {Jha, Ajay and Patil, Sagar H. and Solanki, Bhanu P. and Ribeiro, Ana P. C. and Castro, Carlos A. N. and Patil, Kashinath R. and Coronas, Alberto and Rode, Chandrashekhar V.} } @article {45752, title = {Catalyst-free oxidation of sulfides to sulfoxides and diethylamine catalyzed oxidation of sulfides to sulfones using oxone as an oxidant}, journal = {Research on Chemical Intermediates}, volume = {43}, year = {2017}, month = {DEC}, pages = {6875-6888}, type = {Article}, abstract = {

We describe here our journey from the failure of our attempts in controlled oxidation of sulfides to sulfoxides using an Oxone(A (R))-KBr combination to our success in the development of a catalyst-free protocol for the oxidation of sulfides to sulfoxides using Oxone as an oxidant. We also describe the failure of our attempts at the oxidation of sulfides to sulfones using an excess of Oxone-KBr as well as Oxone, and our success towards the development of a rapid, scalable and chromatography-free protocol for the oxidation of sulfides to sulfones using diethylamine-Oxone as an unprecedented catalyst-oxidant combination. [GRAPHICS] .

}, keywords = {diethylamine, organocatalysis, Oxidation, Oxone, Sulfones, Sulfoxides}, issn = {0922-6168}, doi = {10.1007/s11164-017-3026-0}, author = {Kupwade, R. V. and Khot, S. S. and Lad, U. P. and Desai, U. V. and Wadgaonkar, P. P.} } @article {43945, title = {Developing techno-economically sustainable methodologies for deep desulfurization using hydrodynamic cavitation}, journal = {Fuel}, volume = {210}, year = {2017}, month = {DEC}, pages = {482-490}, type = {Journal Article}, abstract = {The present work, for the first time, describes the efficacy of the cavitation process and compares the cavitation yield for two types of cavitation devices-one employing linear flow for the generation of cavities and other employing vortex flow. The process involves pre-programmed mixing of the organic and aqueous phases, and can be carried out using simple mechanical cavitating devices such as orifice or vortex diode. The process essentially exploits in situ generation of oxidising agents such as hydroxyl radicals for oxidative removal of sulfur. The efficiency of the process is strongly dependent on the nature of device apart from the nature of the organic phase. The effects of process parameters and engineering designs were established for three organic solvents (n-octane, toluene, n-octanol) for model sulfur compound-Thiophene. A very high removal to the extent of 95\% was demonstrated. The results were also verified using commercial diesel. The cavitation yield is significantly higher for vortex diode compared to the orifice. The process has potential to provide a green approach for desulfurization of fuels or organics without the use of catalyst or external chemicals/reagents apart from newer engineering configurations for effective implementation of hydrodynamic cavitation in industrial practice and also appears to be economically sustainable.}, keywords = {Fuel, Oxidation, Petroleum, Pollution Control, Sulphur Removal}, doi = {10.1016/j.fuel.2017.08.106}, author = {Suryawanshi, N.B.}, editor = {Bhandari, V. M.} } @article {43992, title = {Erratum to: catalyst-free oxidation of sulfides to sulfoxides and diethylamine catalyzed oxidation of sulfides to sulfones using oxone as an oxidant}, journal = {Research on Chemical Intermediates}, volume = {44}, year = {2018}, month = {FEB}, pages = {1437{\textendash}1437}, type = {Journal Article}, abstract = {

We describe here our journey from the failure of our attempts in controlled oxidation of sulfides to sulfoxides using an Oxone{\textregistered}{\textendash}KBr combination to our success in the development of a catalyst-free protocol for the oxidation of sulfides to sulfoxides using Oxone as an oxidant. We also describe the failure of our attempts at the oxidation of sulfides to sulfones using an excess of Oxone{\textendash}KBr as well as Oxone, and our success towards the development of a rapid, scalable and chromatography-free protocol for the oxidation of sulfides to sulfones using diethylamine{\textendash}Oxone as an unprecedented catalyst{\textendash}oxidant combination.

}, keywords = {diethylamine, organocatalysis, Oxidation, Oxone, Sulfones, Sulfoxides}, doi = {10.1007/s11164-017-3137-7}, author = {Kupwade, R. V.}, editor = {Khot, S. S.} } @article {44639, title = {Selective oxidation of cyclohexane to cyclohexanone using chromium oxide supported mesoporous MCM-41 nanospheres: probing the nature of catalytically active chromium sites}, journal = {ChemCatChem}, volume = {10}, year = {2018}, month = {AUG}, pages = {3291-3298}, abstract = {

Highly dispersed chromium oxide supported mesoporous MCM-41 nanosphere catalysts have been synthesized using a simple wet impregnation method. This work is devoted to a systematic study to reveal the active Cr sites in chromium oxide supported MCM-41 nanosphere catalysts for the selective oxidation of cyclohexane to cyclohexanone. To probe the nature of the active species, we synthesized 0.5-10wt\% Cr loaded catalysts and characterized them by using XRD, UV/Vis spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, extended X-ray absorption fine structure analysis, X-ray absorption near edge structure analysis, N-2 sorption analysis, FTIR spectroscopy, (SiNMR)-Si-29 spectroscopy, SEM, and TEM. The liquid-phase oxidation of cyclohexane to cyclohexanone (99\% selectivity) was performed under mild reaction conditions, and the results reveal clearly that the 5wt\% Cr loaded catalyst was optimum for the reaction. The initial composition of isolated Cr3+ species in the catalyst is the major factor that influences the enhanced activity for cyclohexane oxidation.

}, keywords = {chromium, heterogeneous catalysis, Nanostructures, Oxidation, supported catalysts}, issn = {1867-3880}, doi = {10.1002/cctc.201800309}, author = {Betsy, Kurisingal J. and Nayak, Chandrani and Lazar, Anish and Krishnan, Athira and Bhattacharyya, Dibyendu and Jha, Shambhu N. and Vinod, Chathakudath P.} } @article {46820, title = {Synthesis of alpha-ketoamides using potassium superoxide (KO2) as an oxidizing agent}, journal = {Tetrahedron}, volume = {76}, year = {2020}, month = {JUN }, pages = {131262}, type = {Article}, abstract = {

A simple and convenient method for the synthesis of alpha-ketoamides by the oxidation of aryl acetamides using potassium superoxide (KO2) as an oxidizing agent is disclosed here. The scope of the developed method is successfully tested with fifteen substrates. In addition, the utility of method has been demonstrated by synthesizing an orexin receptor antagonist, a medicinally interesting compound. (C) 2020 Published by Elsevier Ltd.

}, keywords = {alpha-Ketoamide, Orexin receptor, Oxidation, Potassium superoxide (KO2)}, issn = {0040-4020}, doi = {10.1016/j.tet.2020.131262}, author = {Vasudevan, N. and Routholla, Ganesh and Illa, Giri Teja and Reddy, D. Srinivasa} } @article {47600, title = {Aqueous methanol to formaldehyde and hydrogen on Pd/TiO2 by photocatalysis in direct sunlight: structure dependent activity of nano-Pd and atomic Pt-coated counterparts}, journal = {ACS Applied Energy Materials}, volume = {4}, year = {2021}, month = {NOV }, pages = {13347-13360}, type = {Article}, abstract = {In the present investigation, facet-controlled Pd nanoparticles with nanocube (Pd-NC) and truncated octahedron (Pd-TO) morphologies, and their counterparts with half-a-monolayer of atomic Pt coated (0.5 theta(Pt)-Pd-NC and 0.5 theta(Pt)-Pd-TO) surfaces were prepared. All of them were characterized and evaluated as cocatalyst after supporting them on commercial titania (P25) (Pd-NC/P25, Pd-TO/P25, 0.5 theta(Pt)-Pd-NC/P25, and 0.5 theta(Pt)-Pd-TO/P25) under direct sunlight and/or one sun conditions for the oxidation of methanol to formaldehyde along with solar hydrogen production. Pd-NC/P25 shows higher activity for hydrogen generation compared to Pd-TO/P25; however, activity reversal occurs with the above cocatalysts, but, after Pt-coating with further enhanced activity. The highest conversion of methanol (0.2 mu mol/h.mg) to 100\% selective formaldehyde was observed with 0.5 theta(Pt)-Pd-TO/P25, while other catalysts show significantly lower methanol conversion in the following order: 0.5 theta(Pt)-Pd-TO/P25 > 0.5 theta(Pt)-Pd-NC/P25 > Pd-NC/P25 > Pd-TO/P25. Pt-coated on (111) facets of Pd-TO simulates the activity associated as that of Pt(111) facets and demonstrating the highest and facet dependent activity. The present study is truly in resonance with exploiting the surface properties for heterogeneous catalysis, and highlights that less than a monolayer of Pt is sufficient to simulate the activity as that of bulk Pt. It is worth exploring this concept to other metals and substrates too.}, keywords = {heterogeneous catalysis, Nanomaterials, Oxidation, Photocatalysis, surface modification}, issn = {2574-0962}, doi = {10.1021/acsaem.1c03080}, author = {Nalajala, Naresh and Salgaonkar, Kranti N. and Chauhan, Inderjeet and Mekala, Siva Prasad and Gopinath, Chinnakonda S.} } @article {47133, title = {Improving efficiency for removal of ammoniacal nitrogen from wastewaters using hydrodynamic cavitation}, journal = {Ultrasonics Sonochemistry}, volume = {70}, year = {2021}, month = {JAN}, pages = {105306}, type = {Article}, abstract = {

The present study reports significant improvements in the removal of ammoniacal nitrogen from wastewater which is an important problem for many industries such as dyes and pigment, distilleries and fisheries. Pilot plant studies (capacity, 1 m(3)/h) on synthetic wastewater using 4-amino phenol as model nitrogen containing organic compound and two real industrial effluents of high ammoniacal nitrogen content were carried out using hydrodynamic cavitation. Two reactor geometries were evaluated for increased efficiency in removal-orifice and vortex diode. Effect of initial concentration (100-500 mg/L), effect of pressure drop (0.5-5 bar) and nature of cavitating device (linear and vortex flow for cavitation) were evaluated along with effect of salt content, effect of hydrogen peroxide addition and aeration. Initial concentration was found to have significant impact on the extent of removal: similar to 5 g/m(3) removal for initial concentration of 100 mg/L and up to 12 g/m(3) removal at high concentration of 500 mg/L. Interestingly, significant improvement of the order of magnitude (up to 8 times) in removal of ammoniacal nitrogen could be obtained by sparging air or oxygen in hydrodynamic cavitation and a very high removal of above 80\% could be achieved. The removal of ammoniacal nitrogen by vortex diode was also found to be effective in the industrial wastewaters and results on two different effluent samples of distillery industry indicated up to 75\% removal, though with longer time of treatment compared to that of synthetic wastewater. The developed methodology of hydrodynamic cavitation technology with aeration and vortex diode as a cavitating device was found to be highly effective for improving the efficiency of the conventional cavitation methods and hence can be highly useful in industrial wastewater treatment, specifically for the removal of ammoniacal nitrogen.

}, keywords = {Amino phenol, Cavitation, Oxidation, pollution, Wastewater treatment}, issn = {1350-4177}, doi = {10.1016/j.ultsonch.2020.105306}, author = {Patil, Pravin B. and Bhandari, Vinay M. and Ranade, Vivek V.} } @article {47102, title = {Visible-light-induced controlled oxidation of N-substituted 1,2,3,4-tetrahydroisoquinolines for the synthesis of 3,4-dihydroisoquinolin-1(2h)-ones and isoquinolin-1(2H)-ones}, journal = {Advanced Synthesis \& Catalysis}, volume = {363}, year = {2021}, month = {MAR }, pages = {1390-1400}, type = {Article}, abstract = {

A visible light-rose bengal-TBHP mediated, controlled oxidation of N-substituted 1,2,3,4-tetrahydroisoquinolines is developed for the synthesis of 3,4-dihydroisoquinolin-1(2H)-ones and isoquinolin-1(2H)-ones. The present method feature{\textquoteright}s a broad substrate scope, good functional group tolerances, and the products were prepared in good to excellent yields. The developed methodology further demonstrated in the synthesis of isoindolo[2,1-b] isoquinolin-5(7H)-one (topoisomerase-I inhibitor).

}, keywords = {2, 3, 4-Dihydroisoquinolin-1(2H)-one, 4-tetrahydroisoquinolines, Isoquinolin-1(2H)-one, N-substituted 1, Oxidation, Photocatalysis}, issn = {1615-4150}, doi = {10.1002/adsc.202001266, Early Access Date = JAN 2021}, author = {Bansode, Ajay H. and Suryavanshi, Gurunath} } @article {47735, title = {Wastewater treatment and process intensification for degradation of solvents using hydrodynamic cavitation}, journal = {Chemical Engineering and Processing-Process Intensification}, volume = {166}, year = {2021}, month = {SEP}, pages = {108485}, type = {Article}, abstract = {Industrial wastewater treatment for removal of small concentrations of harmful solvents is pertinent issue in many chemical and pharmaceutical industries. The present work evaluates removal of three common solvents by hydrodynamic cavitation (nominal capacity, 1m(3)/h). Solvent degradation of three solvents viz. octanol, dimethyl formamide and cyclohexanol was studied in the concentration range of 50-200 mg/L and for the pressure drop range of 0.5-5 bar. The vortex based cavitation device (vortex diode) was compared with that of linear flow based device (orifice). Process intensification in the form of aeration and addition oxidizing agent-hydrogen peroxide was also evaluated for synergistic effect. The vortex diode required lower pressure drop and is superior to orifice and process intensification using aeration is most effective. A reduction in TOC to the extent of 74\% could be achieved for octanol (200 ppm) using aeration with cavitational yield of 1202x10(-4) mg/J for vortex diode, yield similar to 10 times of orifice. The degradation depends on the nature of solvent and it was revealed that low values of dielectric constant (epsilon<10) favour degradation. The kinetics was evaluated using rate model based on per-pass degradation factor. The process techno-economic feasibility is useful in industrial wastewater treatment.}, keywords = {Cavitation, Effluent, Organics removal, Oxidation, pollution}, issn = {0255-2701}, doi = {10.1016/j.cep.2021.108485}, author = {Patil, Pravin B. and Bhandari, Vinay M. and Ranade, Vivek V.} } @article {47987, title = {Alpha-angelica lactone catalyzed oxidation of pyrrolidines to lactams}, journal = {European Journal of Organic Chemistry}, volume = {2022}, year = {2022}, month = {AUG}, pages = {e202200712}, type = {Article}, abstract = {

Herein, we report an efficient protocol for the synthesis of gamma-lactams from pyrrolidines and oxygen. The strategy follows a two-step process involving an initial generation alpha-amino alkyl radicals from pyrrolidines and oxygen in presence of 4-dimethylaminopyridine (DMAP) followed by trapping of the radical with oxygen species. This protocol demonstrates good functional group acceptance and provides a direct method to access gamma-lactams. The lactam derivatives were obtained in up to 98 \% yield.

}, keywords = {alpha-Amino alkyl radicals, alpha-Angelica lactone, lactams, Oxidation, Pyrrolidines}, issn = {1434-193X}, doi = {10.1002/ejoc.202200712}, author = {Deepake, Siddharth K. and Kumar, Manish and Kumar, Pawan and Das, Utpal} } @article {48052, title = {Intensified hydrodynamic cavitation using vortex flow based cavitating device for degradation of ciprofloxacin}, journal = {Chemical Engineering Research \& Design}, volume = {187}, year = {2022}, month = {NOV}, pages = {623-632}, type = {Article}, abstract = {

The present work, for the first time, establishes degradation behavior of ciprofloxacin (CIP), a widely used fluoroquinolone group of antibiotics, using vortex flow based hydro-dynamic cavitation (HC) for low to high concentrations of CIP (10 and 100 mg/L). Effect of pressure on the degradation of CIP and TOC reduction was investigated on pilot plant scale (capacity 1 m3/h). Process intensifications using aeration as well as hydrogen per-oxide (H2O2) were also investigated. While aeration did not yield any significant en-hancement, process intensification using H2O2 resulted in similar to 200\% enhancement in the CIP degradation as compared to HC alone. Excellent degradations, to an extent of 79 \& 95\%, were achieved corresponding to high cavitational yields of 7.2 x 10-4 mg/J and 86.8 x 10-4 mg/J for CIP concentrations of 10 and 100 mg/L respectively using the process intensified approach of HC and H2O2, not reported so far for cavitating devices without moving ele-ments. The developed methodology demonstrated 4-7 times improvement in per-pass degradation and low cost with high efficiency compared to the conventional cavitation. The results clearly highlight utility of the process intensified approach using H2O2 for the degradation of CIP even at high concentrations, specifically important for pharmaceutical industries requiring zero liquid discharge norms.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

}, keywords = {Antibiotics removal, ciprofloxacin, Degradation, Oxidation, Wastewater treatment}, issn = {0263-8762}, doi = {10.1016/j.cherd.2022.09.027}, author = {Patil, Pravin B. and Thanekar, Pooja and Bhandari, Vinay M.} } @article {47996, title = {Solvent-assisted cavitation for enhanced removal of organic pollutants - degradation of 4-aminophenol}, journal = {Journal of Environmental Management}, volume = {311}, year = {2022}, month = {JUN }, pages = {114857}, type = {Article}, abstract = {

A new approach of solvent-assisted cavitation process was proposed for degradation of organic pollutants. The process envisages the use of suitable solvent as an additive, (1-5\% v/V), in the conventional cavitation process to enhance the pollutant removal efficiency. A proof of concept was provided for the removal of ammoniacal nitrogen with significantly improved efficiency using solvent-assisted hydrodynamic cavitation (HC) compared to conventional HC. The efficacy of the process was studied on a pilot plant scale (1 m(3)/h) and using vortex flow based vortex diode as a cavitating device. Degradation studies were carried out using a model pollutant, 4-amino phenol and four different solvents as additives, 1-octanol, cyclohexanol, 1-octane and toluene. Relatively polar solvents were found to increase the efficiency of the pollutant removal (\> 65\%) and also increase the rates to an extent of more than 200\%, compared to only HC. A very high removal of ammoniacal nitrogen, more than 90\%, was obtained for solvents 1-octanol and cyclohexanol, indicating the importance of the selection of solvent. Per pass degradation model showed 3 to 4 times increase in the per pass degradation for polar solvents compared to cavitation alone. The results confirm no role of conventional solvent extraction and no specific contamination of wastewater due to the use of solvent as an additive in the process. Further, the cost was 2-3 times lower as compared to the conventional HC. The interesting observations in the proposed process can fuel further research to provide possible improvements in existing methodologies of wastewater treatment, in general, and for removal of ammoniacal nitrogen, in particular.

}, keywords = {Ammoniacal nitrogen, Hydrodynamic cavitation, Oxidation, Pollution Control, Wastewater treatment}, issn = {0301-4797}, doi = {10.1016/j.jenvman.2022.114857}, author = {Patil, Pravin B. and Bhandari, Vinay M.} } @article {48217, title = {Synthesis and crystal structures of Mn(II) and Co(II) complexes as catalysts for oxidation of cyclohexanone}, journal = {Inorganics}, volume = {10}, year = {2022}, month = {JUL}, pages = {100}, type = {Article}, abstract = {

The global demand on adipic usage in the production of plasticizers and synthetic polyamide is increasing. In line with the search for an efficient and energy-conserving way to isolate adipic acid (AA) in good yields, this paper introduces the oxidization of cyclohexanone utilizing two new coordination compounds, [Mn(2,6-pydc)(2)](imi) (1) and [Co(H(2)pza)(2)(H2O)(2)(NO3)].NO3 (2), as catalysts. Compounds 1 and 2 were synthesized by room temperature and refluxing methods, and characterized by spectral analyses (IR and UV-Vis.), SEM, BET, TGA, elemental, and X-ray crystallography. The single crystal structure of compound 1 revealed that pyridinedicarboxylate (2,6-pydc) and imidazole (imi) moieties were coordinated to the Mn(II) atom through imine nitrogen and deprotonated oxygen atoms, to form an undistorted octahedral coordination geometry with the N2O4 donor set. The axial and equatorial planes containing O2, O4, O5, and O7 atoms were from two adjacent 2,6-pydc ligands which formed the unidendate donor ligand; imi, on the other hand, acted as a bidendate donor ligand. For compound 2, the Co(II) atom was being coordinated by two pyrazinamide (H(2)pza) moieties, which acted as an unidendate donor ligand; two water molecules occupying the axial position, and one nitrate molecule occupying the apical position, were within the coordination sphere; a nitrate molecule was disordered outside the coordination sphere. The distance, 4.658 angstrom, between the Co1 atom and the N8 atom of the uncoordinated nitrate molecule, was within the range reported elsewhere. Cyclohexanone peroxidation experiments revealed that compound 1 exhibited unique catalytic performance by giving a 72.8\% yield in adipic acid, in comparison to the 71.3\% yield obtained with compound 2. The yields in AA were maintained by way of recyclability evaluation. The reaction kinetics of compound 2 gave less activation energy, E-a 2938 J mol(-1), while the thermodynamic parameters indicated that the chemical reactivity of cyclohexanone on the active surfaces of compounds 1 and 2 was via monolayer physisorption.

}, keywords = {cobalt, Complexes, cyclohexanone, Imidazole, managanese, Oxidation, pyrazinamide, pyridinedicarboxylate}, doi = {10.3390/inorganics10070100}, author = {Tella, Adedibu C. and Isaac, Aaron Y. and Clayton, Hadley S. and Ogunlaja, Adeniyi S. and Venugopalan, Aswathy T. and Prabu, Marimuthu and Thirumalaiswamy, Raja} } @article {48913, title = {Enhanced degradation of metformin using surface-coated vortex diodes}, journal = {Chemical engineering and processing-process intensification }, volume = {193}, year = {2023}, month = {NOV}, type = {Article}, abstract = {

The present work successfully demonstrates, for the first time, complete degradation of metformin using newer surface-coated vortex diode (SCVD) with copper and nickel coating to provide catalytic activity in the conventional hydrodynamic cavitation (HC) for significantly enhanced degradation efficiency. The SCVDs have dual functionality and the efficacy of catalytic cavitation reactors get enhanced using process intensifications of the type H2O2 addition, pH modification, and combined approach of HC+ pH+ H2O2 apart from the advantage of low pressure drop for the vortex flow based cavitation in vortex diode (Delta P of 1 bar). Complete, 100\%, degradation of metformin (MTF) was achieved within 5 min with integration of optimized H2O2 dose and exceptionally high synergistic index value over 300, indicating extraordinary synergy for both Cu and Ni-SCVD. Acidic condition promote degradation and a complete degradation with a high 43-48\% mineralization was observed using HC+ pH 4+ (1:200) H2O2 with less intermediates formation. The SCVDs reveal remarkable enhancement of similar to 9800\% in per-pass degradation and 1400-3400\% in cavitational yield as compared to conventional cavitation process under similar conditions. The newer SCVDs with catalytic activity can provide more cost-effective solutions for industrial and real-life applications.

}, keywords = {Cavitation, Oxidation, pollution, Technology, Wastewater treatment}, issn = {0255-2701}, doi = {10.1016/j.cep.2023.109572}, author = {Dixit, Divya and Thanekar, Pooja and Bhandari, Vinay M.} } @article {48458, title = {Imine oxidation catalyzed by zinc hydroxyapatite: kinetic studies}, journal = {ChemistrySelect}, volume = {8}, year = {2023}, month = {MAY}, pages = {e202203503}, type = {Article}, abstract = {

The synthesis of N,N-diphenylformamide from N-benzylideneaniline and urea hydrogen peroxide is investigated using a zinc hydroxyapatite (ZnHAP) catalyst. It was found that the catalyst resulted in the highest activity of 91 \% conversion and 40 \% selectivity at 130 degrees C in 2 h. A kinetic model was validated by Langmuir-Hinshelwood-Hougen-Watson (LHHW) at different temperatures and the absence of mass transfer resistance was proved by the Weisz Prater criterion. Effect of different catalysts, catalyst loading, temperature, mole-ratio, and speed of stirring was studied. The as-synthesized catalyst is characterized by FTIR, BET nitrogen adsorption-desorption, TEM, EDX, TPD-NH3, XPS, ICP-MS and XRD. ZnHAP catalyst was found to be stable up to three recycles with no loss in activity.

}, keywords = {heterogeneous catalysis, hydroxyapatite, imines, Oxidation, Reaction kinetics}, issn = {2365-6549}, doi = {10.1002/slct.202203503}, author = {Vishwakarma, Rakhi and Vinod, C. P. and Rathod, Virendra K. and Kantam, Mannepalli Lakshmi} } @article {48727, title = {Improving hydrodynamic cavitation using newer surface-coated cavitation reactors}, journal = {Chemical Engineering Research \& Design}, volume = {199}, year = {2023}, month = {NOV}, pages = {238-251}, type = {Article}, abstract = {

Surface-coated cavitation devices, vortex diode (SCVD) have been reported for the first time for enhancing efficiency of hydrodynamic cavitation (HC). Two surface-coated cavitation reactors using coating of copper and nickel (-50 mu m) were evaluated, also comparing results with conventional reactor vortex diode. The proof of concept is successfully demonstrated for complete degradation of two model organic pollutants, antibioticscephalexin (CFX) and ciprofloxacin (CIP). The surface-coated reactors provide dual activity, and the catalytic effect is highly pronounced with process intensification using H2O2 and/ or pH alternations. Integration of SCVD, pH and H2O2 was the most effective strategy. Complete degradation of the antibiotics was achieved within minutes with H2O2 (-1000 molar ratio) for both Cu and Ni-surface-coated cavitation reactors compared to lower degradation of-19\% for CFX and-37\% for CIP using only HC. An excellent enhancement of over 300\% for CFX degradation at pH 11 and-170\% for CIP degradation at pH 4 was obtained. Huge enhancements in per-pass degradation and cavitational yields (up to 400 times) clearly highlight the utility of the surface-coated cavitation reactors in various applications and for cost-effectiveness.(c) 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

}, keywords = {Hydrodynamic cavitation, Oxidation, pollution, Reactor, Technology, Wastewater treatment}, issn = {0263-8762}, doi = {10.1016/j.cherd.2023.10.002}, author = {Dixit, Divya and Thanekar, Pooja and Bhandari, Vinay M.} } @article {48273, title = {Selective and generic photocatalytic oxidation of alcohol with Pd-TiO2 thin films: butanols to butanal/butanone with different morphologies of Pd and 0.5 theta(Pt)-Pd counterparts}, journal = {Chemistry-An Asian Journal}, volume = {18}, year = {2023}, month = {MAR}, type = {Article}, abstract = {

The present study reports on the photocatalytic oxidation of butanols to butanal/butanone using thin film form of facet-dependent nano-Pd supported on commercial TiO2 under one-sun condition and demonstrates the generic nature. Pd-nanocube (Pd-NC(100)), Pd-truncated octahedron (Pd-TO (100) and (111)), polycrystalline (Pd-PC), and their counterparts with half-a-monolayer Pt-coated on Pd (0.5 theta(Pt)-Pd)) have been used as co-catalyst. A potentially scalable thin film form of Pd/TiO2 photocatalyst, prepared by drop-casting method, has been employed to study oxidation of n-butanol, 2-butanol, and iso-butanol to corresponding aldehyde/ketone. 100\% selectivity is demonstrated to respective aldehyde/ketone with any catalyst used in the present study with varying degree of butanols conversion by NMR. 0.5 theta(Pt)-Pd-TO/TiO2 shows the highest conversion of 2-butanol to butanone (13.6\% in 4 h). Continuous 10 h of reaction with the most active 0.5 theta(Pt)-Pd-TO/P25 catalyst demonstrates 31\% conversion of 2-butanol to butanone, and catalyst recyclability has been demonstrated. The present protocol can be scalable to large scales to maximize the conversion in direct sunlight. Due to its generic nature, the current method can also be applied to many other alcohols and substrate molecules.

}, keywords = {energy conversion, Nanomaterials, Oxidation, Photocatalysis, Sustainability}, issn = {1861-4728}, doi = {10.1002/asia.202201239}, author = {Salgaonkar, Kranti N. and Kale, Sandip R. and Nalajala, Naresh and Mansuri, Sayana and Gopinath, Chinnakonda S.} } @article {48674, title = {Selective and robust Ru catalyst for the aqueous phase aerobic oxidation of furfural to 2-furoic acid}, journal = {ACS Applied Materials \& Interfaces}, volume = {15}, year = {2023}, month = {SEP }, pages = {47004-47015}, type = {Article}, abstract = {

Synthesis of 2-furoic acid (FURA) via oxidation of furfural (FAL) is vital in evolving the biorefinery concept as FURA has numerous important applications in the pharmaceuticals and optic areas. Though few works on this reaction are done, those are marred with shortcomings such as the nonrecyclability of catalyst, dilute solutions, lower yields, or use of H2O2 as an oxidizing agent. Herein, we report catalytic aqueous phase oxidation of FAL to FURA using molecular oxygen as an oxidizing agent. For the synthesis of FURA, various catalysts with a combination of metal (Pt, Pd, Ru) and supports (carbon, Al2O3) were prepared and characterized by multiple techniques (X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS)). Oxidation of FAL carried out over 5 wt \% Ru/C catalyst in the presence of Na2CO3 yielded 83\% of FURA at 120 degrees C and 15 bar oxygen pressure. The catalyst could show potential for reusability as similar activity was achieved after subjecting the spent catalyst to mild reduction treatment (150 degrees C). Studies on the effects of temperature, pressure, and time could help accomplish enhanced yields of FURA. Additionally, learning about the effect of base (weak/strong/solid) revealed that due to the weak basicity of Na2CO3, higher yields could be achieved by maintaining approximately a pH of 11, which is optimal for suppressing side reactions. Under the given conditions, FURA is stable (\>90\%) and also adsorption studies divulge that it is immediately removed from the catalyst surface, and hence higher yields could be achieved in our catalytic system. Using the initial rates methodology, an activation energy of 21.91 kJ mol(-1) was derived and also a high turn over frequency (TOF) (85.9 h(-1)) was observed under optimized conditions.

}, keywords = {2-furoic acid (FURA), Biomass conversion, furfural (FAL), heterogeneous catalyst, Oxidation, ruthenium on carbon etc}, issn = {1944-8244}, doi = {10.1021/acsami.3c09965}, author = {Lokhande, Priya and Dhepe, Paresh L.} } @article {49222, title = {Direct oxidation of alcohols to carboxylic acids using simple and economical Pd@Glu-HTC catalyst: practical and scalable approach towards biomass based value added chemicals}, journal = {Biomass \& Bioenergy}, volume = {187}, year = {2024}, month = {AUG}, pages = {107290}, type = {Article}, abstract = {

Sustainable catalytic transformation of bio-based alcohols to high value-added fine chemicals is an important topic of research. This work described preparation of simple and economical Pd@Glu-HTC catalyst from biomass derived low cost D-glucose. Hydrothermal carbonization of glucose was carried out in first step to synthesize GluHTC support in a simpler, greener, economical and efficient manner followed by incorporation of palladium metal on surface of the catalyst in second step. The catalyst was characterized using techniques such as Fourier Transform Infrared Spectroscopy (FT-IR), Solid-state Cross-Polarization Magic Angle Spinning Carbon-13 (13C CPMAS), Energy-dispersive X-ray spectroscopy (EDAX), Powder X-ray diffraction (P-XRD), X-ray photoelectron spectroscopy (XPS), Thermogravimetric/Differential Thermal Analyzer (TG-DTA), Field emission scanning electron microscopy (FE-SEM) and High-resolution transmission electron microscopy (HR-TEM). The catalyst was evaluated for direct oxidation of alcohols to yield carboxylic acids and exhibited very good catalytic activity for wider substrate scope. Oxidation of alcohols was carried out using milder base, molecular oxygen and water as a solvent to achieve 92-99 \% excellent yields. The practical utility of current strategy was also studied for gram scale synthesis of bio-based value added industrially important chemicals such as furoic acid (flavouring agent and preservative in industry), 2, 5-furan-dicarboxylic acid (monomer to 100 \% fossil-free, recyclable polymer polyethylene furanoate (PEF), tetrahydro-2-furoic acid (production of many drugs) and vanillin (important product of flavor and fragrance industry). Pd@Glu-HTC catalyst was found to be reusable for four recycles and the catalytic performance was retained without any loss in its activity after four cycles.

}, keywords = {Bio-based chemicals, Carbonaceous catalyst, Carboxylic acid, Oxidation}, issn = {0961-9534}, doi = {10.1016/j.biombioe.2024.107290}, author = {Kirdant, Swapnali P. and Bankar, Shubham R. and Jadhav, Vrushali H.} } @article {49233, title = {Efficient glycolysis of used PET bottles into a high-quality valuable monomer using a shape-engineered MnO nanocatalyst}, journal = {CATALYSIS SCIENCE \& TECHNOLOGY}, volume = {14}, year = {2024}, month = {SEP }, type = {Journal Article}, keywords = {Catalyst, kinetics, Nanorods, Oxidation, Oxides, POLY(ETHYLENE-TEREPHTHALATE), WASTE}, issn = {2044-4753}, doi = {10.1039/d4cy00823e}, author = {Swapna, Bhattu and Singh, Nittan and Patowary, Suranjana and Bharali, Pankaj and Madras, Giridhar and Sudarsanam, Putla} } @article {49412, title = {Hypervalent-iodine-mediated base-free oxidative olefination of benzylic amines to access α,β-unsaturated ketones}, journal = {Synlett}, year = {2024}, month = {AUG}, type = {Article; Early Access}, abstract = {

We report a one-pot base-free protocol for the oxidative olefination of benzylic amines promoted by a hypervalent iodine reagent for the synthesis of alpha,beta-unsaturated ketones. Mechanistically, (diacetoxyiodo)benzene oxidizes the benzylic amine to the corresponding imine, which, on reaction with a phenacyl(triphenyl)phosphonium bromide salt and an in situ generated acetoxy anion leads to an alpha,beta-unsaturated ketone. A wide range of alpha,beta-unsaturated ketones were easily accessed through direct oxidative olefination of substituted benzylic amines in good to excellent yields and with high E -selectivity.

}, keywords = {benzylic amines, enones, hypervalent iodine, olefination, Oxidation}, issn = {0936-5214}, doi = {10.1055/s-0043-1775392}, author = {Rupanawar, Bapurao D. and Bansode, Ajay H. and Suryavanshi, Gurunath} } @article {49547, title = {Synthesis of isatins via oxone{\textregistered} /TBAI-mediated on-water oxidation of indoles}, journal = {Synthesis-Stuttgart}, volume = {57}, year = {2025}, month = {MAY}, pages = {1583-1591}, type = {Article}, abstract = {

Isatins and their derivatives are important scaffolds in a wide range of pharmaceuticals, bioactive compounds, and functional materials. Herein we describe a new strategy for the synthesis of isatins from indoles via Oxone (R)/TBAI-mediated oxidative dearomatization of indoles in water. The strategy works well with a variety of N-protected indoles and azaindoles.

}, keywords = {dearomatization, indoles, isatins, Oxidation, Water}, issn = {0039-7881}, doi = {10.1055/a-2492-3240}, author = {Khajuria, Pratiksha and Bag, Debojyoti and Sawant, Sanghapal D.} }