Formate‐Driven, Non‐Enzymatic NAD(P)H Regeneration for the Alcohol Dehydrogenase Catalyzed Stereoselective Reduction of 4‐Phenyl‐2‐butanone

(2,2′‐Bipyridyl)(pentamethylcyclopentadienyl)rhodium complexes are homogeneous catalysts for the formate‐driven, in situ regeneration of the cofactors NADH and NADPH in enantioselective, enzymatic reductions of carbonyl compounds. A non‐enzymatic cofactor regeneration scheme in combination with four NAD(P)H‐dependent alcohol dehydrogenases was tested with the reduction of 4‐phenyl‐2‐butanone. High turnovers and high enantioselectivities were achieved for the formation of the ( R ) and ( S ) alcohols.