Efficient Production of Enantiomerically Pure Chiral Amines at Concentrations of 50 g/L Using Transaminases

Two methods for the efficient (50 g/L) production of optically pure amines from their corresponding ketones using transaminases have been developed. The first method utilizes an ion-exchange resin for in situ product removal allowing the reaction to be carried out a substrate concentration of 50 g/L. The second approach relies upon conversion of the initially formed amine, via spontaneous cyclisation, to a noninhibitory product. Both methods have been demonstrated at 50 mL scale. (R)- and (S)-methylbenzylamine, and (R)- and (S)-6-methyl-2-piperidone have been produced in >90% isolated yield and >99% ee.