Covalent immobilization of the Jacobsen catalyst on mesoporous phenolic polymer: a highly enantioselective and stable asymmetric epoxidation catalyst
The Jacobsen catalyst, N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminomanganese (III) chloride is covalently immobilized on mesoporous phenolic resin through a direct and simple procedure. The immobilization is evident from nitrogen sorption and quantitative XRF measurements. A complex loading of 0.09 mmol g−1 is obtained, corresponding to well dispersed Mn-complexes on the surface of the mesoporous phenolic resin. This novel catalytic system shows good catalytic activity and excellent enantioselectivity in the asymmetric epoxidation of 1,2-dialin. The heterogenized Jacobsen catalyst is demonstrated to be a re-usable and non-leaching catalytic system.