Dynamic Kinetic Resolution of Amines and Amino Acids by Enzyme-Metal Cocatalysis

Methods for the conversion of racemates to single enantiomers are of great importance in organic and pharmaceutical chemistry. Enzymatic kinetic resolution has been most frequently applied for such a conversion. It is particularly useful in preparing both R and S enantiomers at the same time. However, if one enantiomer is needed, the other should be recycled via racemization to enable high yields. Over the last two decades, in situ racemization of the unwanted enantiomers has been intensively studied with the development of metal-based catalysts. Metal-catalyzed racemization can be coupled with enzymatic kinetic resolution for the dynamic kinetic resolution of racemic amines and amino acids, which provides single enantiomeric products with yields approaching 100%. Recent developments in this field are summarized with focus on metal catalysts for racemization.