@article {49190, title = {Chemodivergent dehydrogenative coupling of alcohols by 3d metal catalysts}, journal = {ChemCatChem}, volume = {16}, year = {2024}, month = {JUN }, type = {Article}, abstract = {

Chemodivergent synthesis by transition metal catalysts is a straightforward and sustainable approach to achieving valuable organic compounds. Especially, the chemodivergent dehydrogenative couplings of alcohols with organic motifs to develop various saturated and unsaturated compounds are highly environmentally benign due to the reduced waste generation. In this concept review, we presented the 3d transition metal (Mn, Fe, Co, and Ni)-catalyzed chemodivergent synthesis of imines and amines, saturated and unsaturated carbonyl/alcohol compounds, saturated and unsaturated nitriles, N-heterocycles, and N-/C-alkylated indoles. The discussed reaction commanded two or three different products with high chemoselectivity by changing specific reaction parameters, but keeping the catalyst unchanged. Generally, the acceptorless dehydrogenative coupling (ADC) provides unsaturated moieties, whereas the borrowing-hydrogen (BH) process results in saturated compounds. Text for Table of Contents: An overview of the chemodivergent dehydrogenative coupling of alcohols by the Earth-abundant transition metal catalysts is discussed. image

}, keywords = {3d metals, Alcohols, chemodivergent, dehydrogenative coupling, heterocycles}, issn = {1867-3880}, doi = {10.1002/cctc.202301558}, author = {Bansal, Sadhna and Punji, Benudhar} } @article {49194, title = {Dehydrogenative coupling of alcohols with internal alkynes under nickel catalysis: an access to β-deuterated branched ketones}, journal = {ACS Catalysis}, volume = {14}, year = {2024}, month = {MAY}, pages = {8294-8309}, type = {Article}, abstract = {

In synthetic organic chemistry, unconventional strategies for advanced chemical synthesis pose interesting and challenging problems. Alcohols act as alkylating agents in the C-C and C-N bond-forming reactions via the dehydrogenative borrowing hydrogen strategy in traditional transition metal catalysis; however, as an acylating agent in the C-C bond-forming reactions is challenging and rarely reported. Here, we report the dehydrogenative coupling of benzylic alcohols with internal alkynes under nickel(II) catalysis, wherein alcohol is used as an acylating agent. This reaction system affords a wide range of alpha-branched aryl ketone derivatives with zero waste generation through the umpolung borrowing hydrogen strategy. Moreover, we have demonstrated the chemodivergent applications of the alpha-disubstituted ketones to other valuable building blocks, including large-scale synthesis of beta-deuterated branched ketones. Several spectroscopic studies, intermediate identification, and density functional theory calculations were performed to elucidate the reaction mechanism.

}, keywords = {Alcohols, alpha-branched aryl ketones, dehydrogenative coupling, internal alkynes, nickel catalysis, pseudoumpolung}, issn = {2155-5435}, doi = {10.1021/acscatal.3c06091}, author = {Subaramanian, Murugan and Gouda, Chandrakant and Roy, Triptesh Kumar and Ganesan, Sivakumar and Banerjee, Subhrashis and Vanka, Kumar and Balaraman, Ekambaram} } @article {49023, title = {Nickel-catalyzed chemodivergent coupling of alcohols: efficient routes to access α,α-disubstituted ketones and α-substituted chalcones}, journal = {Chemistry- a european journal}, volume = {30}, year = {2024}, month = {MAR}, type = {Article}, abstract = {

Chemodivergent (de)hydrogenative coupling of primary and secondary alcohols is achieved utilizing an inexpensive nickel catalyst, (6-OH-bpy)NiCl2. This protocol demonstrates the synthesis of branched carbonyl compounds, alpha,alpha-disubstituted ketones, and alpha-substituted chalcones via borrowing hydrogen strategy and acceptorless dehydrogenative coupling, respectively. A wide range of aryl-based secondary alcohols are coupled with various primary alcohols in this tandem dehydrogenation/hydrogenation reaction. The nickel catalyst, along with KOtBu or K2CO3, governed the selectivity for the formation of branched saturated ketones or chalcones. A preliminary mechanistic investigation confirms the reversible dehydrogenation of alcohols to carbonyls via metal-ligand cooperation (MLC) and the involvement of radical intermediates during the reaction. The chemodivergent nickel-catalyzed approach provides alpha,alpha-disubstituted ketones from aryl-substituted secondary alcohols and benzyl alcohols via the borrowing hydrogen (BH) strategy in the presence of KOtBu, whereas exclusively alpha-substituted chalcones were accomplished in the presence of mild base K2CO3 through an acceptorless dehydrogenative coupling (ADC) strategy. image

}, keywords = {Alcohols, dehydrogenative coupling, Metal-ligand cooperation, Nickel, substituted carbonyl compounds}, issn = {0947-6539}, doi = {10.1002/chem.202304082}, author = {Bansal, Sadhna and Punji, Benudhar} }