Iron Catalyzed Highly Enantioselective Epoxidation of Cyclic Aliphatic Enones with Aqueous H_2O_2

摘要

An iron complex with a C_1-symmetric tetra-dentate N-based ligand catalyzes the asymmetric epoxidation of cyclic enones and cyclohexene ketones with aqueous hydrogen peroxide, providing the corresponding epoxides in good to excellent yields and enantioselectivities (up to 99% yield, and 95% ee), under mild conditions and in short reaction times. Evidence is provided that reactions involve an electrophilic oxidant, and this element is employed in performing site selective epoxidation of enones containing two alkene sites.