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Abstract

An process for epoxidizing diversely functionalized olefins by oxorhenium catalysis employs conditions which control water concentration. By controlling water concentration, one can maximize monoperoxo complex formation and increase turnover which subsequently reduces diol side products obtained from epoxide ring opening and increases the yield of the desired epoxide product. The optimal range of water concentrations is 0.50-80.0 mol %. Using less than 0.5 mol % water does not result in practical turnovers and 1.0 equivalent of water (or more) is detrimental to the lifetime of the active catalytic species formed. More particularly, there are four aspects to controlling water concentration: 1) anhydrous oxidants using trialkylsilyl peroxides and an in situ source of BTSP eliminating the need for its isolation; 2) water removal agents including molecular sieves (Aldrich, 3 .ANG., 4 .ANG.) and common inorganic dehydrating agents; 3) rhenium catalysts; and 4) a boiling reactor process in the context of oxorhenium catalyzed epoxidation.

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First Claim