Formal Asymmetric Biocatalytic Reductive Amination

All for one: A combination of three biocatalysts (ω-transaminase, alanine dehydrogenase, and an enzyme such as formate dehydrogenase for cofactor recycling) catalyze a cascade to achieve the asymmetric transformation of a ketone into a primary α-chiral unprotected amine through a formal stereoselective reductive amination (see scheme). Only ammonia and the reducing agent (formate) are consumed during this reaction.