@article { ISI:000239869200010,
	title = {Organosilanesulfonic acid-functionalized Zr-TMS catalysts: synthesis, characterization and catalytic applications in condensation reactions},
	journal = {Applied Catalysis A-General},
	volume = {310},
	year = {2006},
	month = {AUG},
	pages = {79-90},
	publisher = {ELSEVIER SCIENCE BV},
	type = {Article},
	address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	abstract = {<p>Organosilanesulfonic acid (-Si-R3S-R4SO3H, OSA)-functionalized mesoporous Zr-TMS (Zr-TMS-Si-R3S-R4SO3H, Zr-TMS-OSA) was synthesized either by post-synthetic modification of Zr-TMS (zirconia-based transition metal oxide mesoporous molecular sieves) with 3-mercaptopropyltrimethoxysilane (3-MPTS) and further with 1,4-butanesultone (1,4-BS) or by in situ one-pot synthesis procedure. A number of physico-chemical characterization techniques have been used to show that the organosilanesulfonic acid groups were anchored on to the walls of Zr-TMS. MCM-41-Si-R3S-R4SO3H-20 (MCM-41-OSA-20) was also prepared by post-synthesis procedure for comparison. Physico-chemical properties of in situ made A-Zr-OSA-20, Zr-TMS-SO3H-20 and MCM-41-OSA-20 were compared with Zr-TMS-OSA catalysts. The catalytic activity of the materials was tested in liquid phase condensation of aniline with p-formaldehyde to 4,4{\textquoteright}-diaminodiphenylmethane (4,4{\textquoteright}-DADPM). Results showed that Zr-TMS-OSA catalysts were more active than Zr-TMS-SO3H-20, MCM-41-OSA-20 and A-Zr-OSA-20 and more selective than Zr-TMS-SO3H-20 and A-Zr-OSA-20 catalysts. (C) 2006 Elsevier B.V. All rights reserved.</p>},
	keywords = {Acid catalyst, condensation of aniline, mesoporous ZrO2, organic functionalization, organosilanesulfonic acid},
	issn = {0926-860X},
	doi = {10.1016/j.apcata.2006.05.024},
	author = {Chidambaram, M. and Venkatesan, C. and Singh, A. P.}
}
@article { ISI:000293435400011,
	title = {Solvent-free mukaiyama-aldol condensation catalyzed by Ce-Al-MCM-41 mesoporous materials},
	journal = {Microporous and Mesoporous Materials},
	volume = {144},
	number = {1-3},
	year = {2011},
	note = {16th IZC/7th IMMS Conference, Sorrento, ITALY, JUL 04-09, 2010},
	month = {OCT},
	pages = {82-90},
	publisher = {ELSEVIER SCIENCE BV},
	address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	abstract = {<p>MCM-41 samples containing Ce4+ and Al3+ in the network, designated as Ce-x-Al-MCM-41 (x = 0.0-0.04), were synthesized and characterized systematically. These samples exhibited higher catalytic activity for Mukaiyama-aldol condensations to produce beta-hydroxy carbonyl compounds under the solvent free conditions, compared to the samples containing either of the two cations. The product yield was found to depend on the electron donating/withdrawing characteristics of reactant molecules being responsible for the observed trend. Series of solvents were also investigated but considerably high yield of aldol products (similar to 95\%) could be achieved without using any solvents. In all the cases, the selectivity was found to be 100\%, typical of such Mukaiyama-aldol condensations. The higher catalytic activity of Ce-x-Al-MCM-41 is explained on the basis of certain new acid sites generated due to co-incorporation of Ce and Al cations. Published by Elsevier Inc.</p>},
	keywords = {Acid catalyst, Ce-Al-MCM-41, Silyl enol ether and aldehyde, Silyl ketene acetal},
	issn = {1387-1811},
	doi = {10.1016/j.micromeso.2011.03.027},
	author = {Kalita, Pranjal and Gupta, Narendra M. and Kumar, Rajiv}
}
