Styrene Oxide Isomerase-Catalyzed Meinwald Rearrangement in Cascade Biotransformations: Synthesis of Chiral and/or Natural Chemicals.

Styrene oxide isomerase (SOI) catalyzes the Meinwald rearrangement of aryl epoxides to carbonyl compounds via a 1,2-trans-shift in a stereospecific manner. A number of cascade biotransformations with SOI-catalyzed epoxide isomerization as a key step have been developed to convert readily available substrates into valuable chiral chemicals. Cascade conversion of terminal or internal alkenes into chiral acids, alcohols or amines was achieved, which involved SOI-catalyzed enantio-retentive isomerization of terminal epoxides via 1,2-H shift, or internal epoxides via 1,2-methyl shift. SOI-involved cascades were also developed to convert racemic epoxides into chiral acids or amines via dynamic kinetic resolution. Additionally, combining SOI-catalyzed isomerization with enantioselective C-C bond forming enzymes enabled the synthesis of chiral amino acids or amino alcohols from racemic epoxides. Finally, integration of SOI-involved cascades with biosynthesis pathways allowed for the direct utilization of renewable substrates for the sustainable synthesis of high-value natural chemicals such as alcohols, acids, and esters.