Chiral Mn(III) salen complexes immobilized directly on pyrolytic waste tire char for asymmetric epoxidation of unfunctionalized olefins

Two kinds of chiral Mn(III) salen complexes were synthesized and directly immobilized on pyrolytic waste tire char (PWTC) without modification of any organosilicon, which was an economic support, having rich oxy functionalized groups inherently. The as-prepared heterogeneous catalysts were characterized by X-ray photoelectron spectra (XPS), N-2 sorption, Fourier transform infrared spectra (FT-IR) and thermogravimetric analysis (TG), and possessed of good catalytic performance in asymmetric epoxidation of unfunctionalized olefins. They obtained higher enantiomeric excess (ee) values than that of homogeneous catalysts for asymmetric epoxidation of 1-phenylcyclehexene and could be recycled three times. (C) 2012 Elsevier B.V. All rights reserved.