Development of Supported Salen Catalysts

Significance

Poly(norbornene)-supported salen complexes of manganese and cobalt were developed. The monofunctionalized Mn- and Co-sa­lenes 2 and 3 bearing the norbornene unit were prepared in 77% and 83% yield, respectively. Ring-opening metathesis polymerization (ROMP) of the analytically pure and fully characterized monomers using the 3rd-generation Grubbs catalyst, gave 5 and 6. The copolymerization of 2 and 3 with the unfunctionalized norbornene 4 gave products 7-12. The resulting polymer-supported Mn- and Co-salene complexes were used for the asymmetric epoxidation of olefins and the hydrolytic kinetic resolution of epoxides. All polymer-supported catalysts showed outstanding catalytic activities and selectivities comparable to the original salene catalysts (reported by Jacobsen).