Iridium-Catalyzed Hydrogenation of Carboxylic Acid Esters

The first selective iridium-catalyzed hydrogenations of esters are presented. By using a commercially available iridium pincer complex more than 20 different aromatic, aliphatic, and (hetero)cyclic esters are reduced to the corresponding alcohols in moderate to very good yields. An outer-sphere mechanism is proposed on the basis of our computational analysis.