Directed Evolution as a Method To Create Enantioselective Cyclohexanone Monooxygenases for Catalysis in Baeyer-Villiger Reactions

摘要

The Baeyer-Villiger (BV) reaction of ketones with hydro-peroxides affords the corresponding esters or lactones.The reaction is accelerated by acids,bases,or metal complexes,and enantioselective catalysis is possible in certain cases Alternatively,flavin-dependent enzymes such as cyclohexa-none monooxygenases (CHMOs) can be used as biocatalysts in asymmetric BV reactions.In this enzymatic process dioxygen (air) reacts with the enzyme-bound flavin (FAD) to form an intermediate hydroperoxide,which in the deproto-nated form initiates the BV reaction by transferring one oxygen atom originating from O_2 to the substrate (ketone),the other being ultimately reduced to water.