Hydrogenation of α- and β-Keto Esters under Atmospheric Pressure Catalyzed by a Metal–Ligand Bifunctional Iridium Catalyst

The hydrogenation of α- and β-keto esters to α- and β-hydroxy esters under atmospheric pressure has been realized. Using 1 mol % of the iridium complex [Cp*Ir(2,2′-bpyO)(OH 2 )] as the catalyst, a range of products were isolated in high yields. This protocol is attractive due to high atom efficiency, and milder and safer conditions. It was found that functional groups on the bpy ligand play a vital role in tuning the catalytic performance of these iridium complexes. DFT calculations and practical potential were also presented.