Synthesis of 4-phenylpyrrolidin-2-one via dynamic kinetic resolution catalyzed by ω-transaminases

Enantiomerically enriched 4-phenylpyrrolidin-2-one was prepared within only three steps starting from a commercial compound employing dynamic kinetic resolution (DKR) as the key asymmetric step. To the best of our knowledge, for the first time a DKR was performed involving an enzymatic enantioselective amination reaction catalyzed by ω-transaminases. Careful optimization of co-solvent and pH conditions allowed enhancing the enantioselectivity. The general method allows access to 4-arylpyrrolidin-2-ones derivatives, the cyclic analogues of γ-aminobutyric acid (GABA) derivatives.