Enzyme‐Catalyzed Asymmetric Reduction of Ketones

Abstract

Abstract The enantioselective transformation of a prochiral C=O double bond into the corresponding reduced CH–OH single bond plays a major role in asymmetric synthesis since this type of transformation represents a straightforward and an atom‐economical approach toward the synthesis of optically active alcohols. Owing to the importance of chiral alcohols in the field of chiral drug production, enantioselective ketone reduction also gained tremendous industrial interest. For the enantioselective reduction of ketones, numerous efficient catalytic routes have been developed up‐to‐date. As outstanding chemocatalytic technologies, metal‐catalyzed asymmetric hydrogenation of ketones and borane reduction are widely applied on industrial scale. Complementing these chemocatalytic technologies for the production of enantiomerically pure alcohols, enantioselective biocatalytic reduction of ketones turned out to be a highly efficient and competitive alternative technology. Notably, biocatalytic ketone technologies already made the “jump” from an interesting academic synthetic tool toward an industrially feasible technology platform. Besides high catalytic efficiency and excellent enantioselectivities, robustness and industrial large‐scale feasibility are further key features of enantioselective ketone reduction processes with biocatalysts. Thus, it is no surprise that the suitability for industrial purpose, in particular, for large‐scale manufacture of enantiomerically pure alcohols as drug intermediates, has been already demonstrated by a broad range of technical applications in the chemical and pharmaceutical industry.