Enzyme catalysed deracemisation and dynamic kinetic resolution reactions

New catalysts and reaction conditions have been developed for the dynamic kinetic resolution or deracemisation of racemic mixtures of chiral compounds. Specific functional groups that lend themselves particularly well to this approach include chiral secondary alcohols, a-amino acids, amines and carboxylic acids. A general theme of these processes is the combination of an en antioselective enzyme with a chemical reagent, the latter being used either to racemise the unreactive enantiomer or alternatively recycle an intermediate in the deracemisation process. In some examples of dynamic kinetic resolution, a second enzyme (racemase) is used to interconvert the enantiomers of the starting material.