Efficient Epoxidation of Olefins with Hydrogen Peer-oxide Catalyzed by Novel Silicotungstate

摘要

Epoxides are an important class of industrial chemicals that have been used as chemical intermediates. Catalytic epoxidation of olefins affords an interesting production technology. We found a widely usable green route to the production of epoxides: A silicotungstate compound, [gamma-SiW_(10)O_(34) (H_2O)_2]~(4-), is synthesized by protonation of a divacant, lacunary, Keggin-type polyoxometalate of [gamma-SiW_(10)O_(36)]~(8-) and exhibits high catalytic performance for the epoxidation of various olefins, including propylene, with a hydrogen peroxide at 305 K. The effectiveness of this catalyst s evidenced by >=99 percent selectivity to the corresponding epoxide, >=99 percent efficiency of hydrogen peroxide utilization, high stereospecificity, and easy recovery of the catalyst from the homogeneous reaction mixture.