Biocatalyzed Enantiomerically Pure Production of (S)‐Phenyl(thiophen‐2‐yl)methanol

Abstract

Chiral aryl heteroaryl methanols are important precursors for the synthesis of pharmaceutically important molecules. The aims of this study were to use a biocatalyst that could efficiently bioreduce phenyl(thiophen‐2‐yl)methanone 1 to (S)‐phenyl(thiophen‐2‐yl)methanol 2, to identify the impact of the physicochemical factors that might affect the bioreduction by the biocatalyst, and to obtain multigram production of aryl heteroaryl secondary alcohol 2 with the biocatalyst under optimized conditions. Over the years, the (S)‐phenyl(thiophen‐2‐yl)methanol was synthesized on a small scale using a chemical catalyst without its enantiomerically pure form. In this study, Lactobacillus paracasei BD101 was used for the asymmetric reduction of phenyl(thiophen‐2‐yl)methanone to (S)‐phenyl(thiophen‐2‐yl)methanol in the large‐scale production. The asymmetric bioreduction conditions were systematically optimized, and the production of 3.77 g of (S)‐phenyl(thiophen‐2‐yl)methanol was carried out in enantiomerically pure form >99% enantiomeric excess (ee), >99% conversion, and 90% yield. This method obtained with this biocatalyst is a process that can be used industrially in terms of conversion, ee, and yield. This study provides guidance for the application of L. paracasei BD101 in the production of optically active aryl heteroaryl alcohols.