Dynamic kinetic resolutions and asymmetric transformations by enzymes coupled with metal catalysis

The combination of enzyme and metal catalysis is described as a useful method for the synthesis of optically active compounds. A key feature of this new methodology is the use of metal catalysts for the in situ racemization of enzymatically unreactive enantiomers in the enzymatic resolution of racemic substrates. So far, two combinations - lipase-ruthenium and lipase-palladium - have been developed for the efficient dynamic kinetic resolution of alcohols and amines. The use of these combinations has also been extended to catalysis of the asymmetric transformation of ketones, their enol acetates, and ketoximes. In most cases, enzyme-metal combination catalysis has provided good yields and high optical purities.