EPOXIDATION OF UNFUNCTIONALIZED OLEFINS C ATALYZED BY UNSYMMETRIC SCHIFF-BASE-MN(III) COMPLEXES

The selective epoxidation of unfunctionalized olefins (styrene, cycloh exene, alpha-methylstyrene) catalyzed by synthesized unsymmetric Schif f-base-Mn (II) complexes Mn(CBP-phen-XSal)Cl[X = H, Cl, Br, NO2, CH3, OCH3] and the symmetric analogs Mn(CBP-R-CEP)Y[R=CH2CH2, CH(CH3)CH2, C 6H4; Y=Cl, OAc] was investigated under mild conditions with iodosylben zene as the terminal oxidant. The results show that the unsymmetric co mplexes Mn(II)(CBP-phen-XSal)Cl is an effective system in catalyticall y selective olefin-epoxidation; the smaller the binding energy of Mn(I I), the more effective in epoxidation; the highest epoxidation yields of the mentioned three olefins are 73%, 100% and 92% respectively.