One‐Pot Three‐Step Consecutive Transformation of L‐α‐Amino Acids to (R)‐ and (S)‐Vicinal 1,2‐Diols via Combined Chemical and Biocatalytic Process

Abstract

AbstractOptically pure vicinal 1,2‐diols are versatile chiral building blocks in the fine chemical and pharmaceutical industries. L‐α‐amino acid is a good feedstock source for high value‐added product production since it is inexpensive and renewable. However, conversion of L‐α‐amino acids to enantioenriched vicinal 1,2‐diols remains a significant challenge. In this study, combining a simple chemical process and a three‐enzyme cascade biocatalysis system, we have successfully implemented a one‐pot sequential process for the transformation of L‐α‐amino acids into enantiopure vicinal 1,2‐diols in aqueous medium. Firstly, the NaBH4‐H2SO4 system converted L‐α‐amino acids to (S)‐amino alcohols via amino acid carboxyl reduction. Secondly, the three‐enzyme (transaminase, carbonyl reductase and glucose dehydrogenase) cascade biocatalysis system converted amino alcohols to enantiopure vicinal 1,2‐diols via amino alcohol deamination, α‐hydroxy ketone asymmetric reduction and cofactor regeneration. Taking advantage of the two different reaction systems, chiral vicinal 1,2‐diols could be obtained from L‐α‐amino acids with high yields (69–90 %) and excellent ee values (91–>99 % ee).