Unexpected role of anionic ligands in the ruthenium-catalyzed base-free selective hydrogenation of aldehydes

Abstract

Bigger and better: The replacement of anionic chloride ligands in Noyori-type [(diamine)(diphosphine)RuCl2] catalysts with bulky carboxylate ligands enabled the efficient selective hydrogenation of a variety of aldehydes under base-free conditions (see scheme). Turnover numbers of up to 100 000 were reached in the presence of a bulky carboxylic acid co-catalyst. This type of catalytic system probably operates through an inner-sphere mechanism. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.