Stereoselective synthesis of trisubstituted epoxides via cobalt catalysis

Abstract

Catalytic epoxide synthesis by transition-metal catalysis offers an atom- and step-economical route from readily available aldehydes and diazocarbonyl compounds. Herein we report that a cobalt catalyst could promote epoxide synthesis under ligand-free conditions with excellent E selectivity, which is different from previous reports. The product could be generated in moderate to good yields with excellent stereoselectivity. Preliminary mechanism studies show that the present catalytic system features a nucleophilic addition mechanism, distinctive from other transition-metal catalyzed epoxide syntheses.