Manganese (III) salen complex anchored onto MCM-41 as catalyst for the aerobic epoxidation of olefins

An unsymmetrical manganese (III) salen complex was anchored onto the surface of MCM-41 by a multi-step grafting method. The resulting material was characterized by FT-IR, X-ray diffraction, DR U-V-Vis, nitrogen adsorption and ICP. The catalytic activity of the immobilized catalyst was tested in the aerobic epoxidation of olefins. The immobilized catalyst showed relatively high activity and epoxide selectivity in the aerobic epoxidation of cyclohexene, styrene, 1,2-dihydronaphthalene and alpha-methylstyrene. The immobilized catalyst can be reused six times. However, the conversion of cyclohexene decreased from more than 99% in the first run to 73.7% in the sixth, while 64.8% of manganese leaching was observed. (c) 2006 Elsevier Inc. All rights reserved.