Synthesis of Epoxides Catalyzed by a Halide-Free Reaction-Controlled Phase-Transfer Catalytic System: [(CH3(CH2)17)2N(CH3)2]3[PW4O32]/H2O2/Dioxan/Olefin

The epoxidation of alkenes was successfully catalyzed by a recyclable catalytic system: [(CH3(CH2)17)2N(CH3)2]3[PW4O32]/H2O2/dioxan/olefin. This new catalytic system is not only capable of catalyzing homogeneous epoxidation of alkenes with a unique reaction-controlled phase-transfer character, but also avoids the use of chlorinated solvents. The reactions were conducted in a biphasic mixture of aqueous H2O2/dioxan, and many kinds of alkenes could be efficiently converted to the corresponding epoxides in high yields. Both new and used [(CH3(CH2)17)2N(CH3)2]3[PW4O32] catalyst was characterized by 31P magic angle spin NMR, and IR.