Ir-Catalyzed Reduction of Carbonyl Compounds Using Biogenetic Alcohols

Abstract

Biomass has gained great attention as an alternative to fuel-derived chemicals. This report concerns new catalytic systems consisting of [IrCp*Cl2]2 (Cp*: Pentamethylcyclopentadienyl) for the reduction of aldehyde and biogenetic alcohols as hydrogen sources. [IrCp*Cl2]2 has been used as a transfer hydrogenation catalyst using fossil fuel-derived alcohols as hydrogen sources in the presence of a base. In contrast, our system does not require any base, and the reaction can proceed in water. Various types of biogenetic alcohols can be used as hydrogen sources, such as monosaccharides, oligosaccharides, and glycerol. Aromatic and aliphatic aldehydes, as well as ketones, were successfully reduced to the corresponding alcohols in the present system.