Bio- and chemo-catalytic preparations of chiral epoxides

Chiral epoxides are one of the increasingly used intermediates for the production of chiral pharmaceuticals. Chiral epoxides can react with a variety of reagents because of the polarity and ring-strain of the epoxide ring. Chiral epoxides can be prepared based on various chemical and biological approaches. Chemo-catalytic asymmetric epoxidation of prochiral olefin substrates and Co(III)-salen-catalyzed hydrolytic kinetic resolutions of racemic epoxides have been successfully implemented as production methods in industrial scales. Bio-catalytic transformations including direct epoxidation of prochiral substrates by monooxygenase or peroxidase, enantioselective hydrolysis of racemic epoxides by epoxide hydrolase, and lipase-mediated kinetic resolutions have been considered as alternatives due to their excellent enantioselectivity and regioselectivity. In this paper, bio- and chemo-catalytic preparations of chiral epoxides are reviewed. Industrial applications of chemo- and bio-catalytic preparations of chiral epoxides will be discussed herein.