Liquid-phase epoxidation of olefins by manganese oxide octahedral molecular sieves

摘要

Manganese oxide octahedral molecular sieves with a cryptomelane structure (OMS-2) were used to catalyze the oxidation of cyclic olefins and benzylic double bonds with ternary-butyl hydroperoxide (TBHP) as the oxidant.OMS-2 showed good catalytic activity with high selectivity under mild conditions (substrate:oxidant molar ratio of 1:1) for the oxidation of different substrates that were studied.Cyclooctene gets oxidized to cyclooctene epoxide selectively in the presence of OMS-2 among the different substrates used for oxidation.The order of reaction with respect to cyclooctene was determined to be pseudo-first order using OMS-2 and excess TBHP.The effects of time,reaction temperature,solvents,and amount of catalyst were investigated.Various reaction conditions and conversion of cyclooctene were maximized at 60 deg C using acetonitrile as the solvent.