@article {CSIR, title = {Hydrogenation of polar bonds catalysed by ruthenium-pincer complexes}, journal = {Ruthenium in Catalysis}, volume = {48}, number = {5}, year = {2014}, note = {3rd International Conference on Advances in Computing, Communications and Informatics (ICACCI), New Delhi, INDIA, SEP 24-27, 2014}, month = {MAR}, pages = {19-43}, publisher = {IEEE Commun Soc; IEEE Syst Man \& Cybernet Soc; Galgotias Coll Engn \& Technol; Hochschule Offenburg Univ Appl Sci; Int Neural Network Soc; India Chapter \& Res Publishing Serv; Madhyam; WizIQ; ICACCI; IEEE}, address = {HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY}, abstract = {

Catalytic hydrogenation of polar bonds using molecular hydrogen is an important, atom-economical synthetic reaction. Classical reduction methods of polar bond often require reactive metal-hydride reagents in stoichiometric amount and produce copious waste. Hydrogenation of carbonyl compounds in particular provides {\textquoteleft}green{\textquoteright} approaches to synthetically important building blocks, such as alcohols and amines. We have designed and synthesized several ruthenium-based pincer catalysts for unprecedented hydrogenation reactions including: (1) amides to alcohols and amines, (2) biomass-derived di-esters to 1,2-diols and (3) CO2 and CO derivatives to methanol. These atom-economical reactions operate under neutral, homogeneous conditions, at mild temperatures, mild hydrogen pressures, and can operate in absence of solvent with no generation of waste. The postulated mechanisms involve metal-ligand cooperation (MLC) by aromatization-dearomatization of the heteroaromatic pincer core.

}, keywords = {Amides, Carbon dioxide, Esters, Hydrogen, Hydrogenation, Metal-ligand cooperation, Pincer complexes, ruthenium}, isbn = {978-3-319-08482-4; 978-3-319-08481-7}, issn = {1436-6002}, doi = {10.1007/3418_2014_77}, author = {Balaraman, Ekambaram and Milstein, David}, editor = {Bruneau, C. and Dixneuf, P. H.} } @article {45459, title = {Photocatalysis enabling acceptorless dehydrogenation of diaryl hydrazines at room temperature}, journal = {ACS Catalysis}, volume = {8}, year = {2018}, month = {AUG}, pages = {7727-7733}, type = {Article}, abstract = {

Aromatic azo compounds are privileged structural motifs, and they exhibit a myriad of pharmaceutical as well as industrial applications. Here, we report a catalytic acceptorless dehydrogenation of diarylhydrazine derivatives to access a wide variety of aryl-azo compounds with the removal of molecular hydrogen as the sole byproduct. This distinctive reactivity has been achieved under dual catalytic conditions by merging the visible-light active [Ru(bpy)(3)](2+) as the photoredox catalyst and Co(dmgH)(2)(py)Cl as the proton-reduction catalyst. The reaction proceeds smoothly under very mild and benign conditions and operates at ambient temperature. This dual catalytic approach is highly compatible with many different functional groups and has a broad substrate scope. We have also demonstrated the reversible hydrogen storage and release phenomenon on hydrazobenzene/azobenzene couple to show the utility of these compounds as hydrogen storage materials. Further diversification of azobenzene was shown by a transition metal-catalyzed azo-group-directed ortho-C-H bond functionalization.

}, keywords = {acceptorless dehydrogenation, Azo benzene, dual catalysis, Hydrogen, photoredox catalysis}, issn = {2155-5435}, doi = {10.1021/acscatal.8b01579}, author = {Sahoo, Manoj K. and Saravanakumar, Krishnasamy and Jaiswal, Garima and Balaraman, Ekambaram} } @article {46993, title = {Manganese-catalyzed alpha-olefination of nitriles with secondary alcohols}, journal = {ACS Catalysis}, volume = {10}, year = {2020}, month = {JAN}, pages = {947-954}, type = {Article}, abstract = {

An expedient catalytic approach for alpha-olefination of nitriles using secondary alcohols with the liberation of molecular hydrogen and water as the only byproducts is reported. This reaction is catalyzed by a molecularly defined manganese(I) pincer complex and operates in the absence of any hydrogen acceptors. A broad range of substrates including cyclic, acyclic, and benzylic alcohols, as well as various nitrile derivatives, such as arylmethyl and heteroarylmethyl nitriles, are employed in the reaction to provide a diverse range of alpha-vinyl nitriles in good to excellent yields. Mechanistic studies showed that the reaction proceeds via dehydrogenative pathway and the activation of alpha(C-H) bond of the alcohol is the rate-determining step.

}, keywords = {acceptorless dehydrogenation, Alcohol, alpha-olefination, Hydrogen, manganese}, issn = {2155-5435}, doi = {10.1021/acscatal.9b02811}, author = {Yadav, Vinita and Landge, Vinod G. and Subaramanian, Murugan and Balaraman, Ekambaram} }