Selective hydrogenation of carbonyl compounds and olefins using an efficient combination of homogeneous RuCl3/1,10-Phenanthroline

Abstract

Hydrogenation of organic compounds with molecular hydrogen is an atom economic reaction and plays a key role in chemical synthesis. Here, we report the hydrogenation of carbonyl compounds to alcohols as well as alkenes to alkanes with easy-to-handle reagents under 10 bar hydrogen pressure. The hydrogenation reactions are executed with readily available RuCl3·xH2O/1,10-phenanthroline and show high catalytic efficiency in the presence of other reactive functional groups (e.g., halogens and hydroxyl) under mild reaction conditions. Moreover, the chemoselectivity and robustness of the Ru catalytic system found their merit in the hydrogenation of lignocellulosic biomass-derived substrates (e.g., vanillin, 5-HMF, and eugenol) including linoleic acid methyl ester, affording the corresponding products in good to high yields. Density functional theory (DFT) calculations were carried out in conjunction with the Laplacian of electron density and natural bond orbital (NBO) analysis to unravel the mechanistic insights into the hydrogenation of the carbonyl compounds.