Enzymatic asymmetric synthesis of the silodosin amine intermediate

Abstract Various enantiocomplementary ω-transaminases (ωTAs) were investigated in kinetic resolution and asymmetric reductive amination reactions to prepare silodosin amine. Whilst the enzymatic kinetic resolution gave moderate to good results with respect to the yield and enantioselectivity, the asymmetric reductive amination proved to be superior. The best results were obtained with the ωTA originating from ( R )- Arthrobacter sp. which afforded the desired bioactive ( R )-enantiomer in enantiomerically pure form (ee >97%) at excellent conversion (conv. >97%) under mild and benign reaction conditions.