Reaction-controlled phase-transfer catalysis for propylene epoxidation teapropylene oxide

The epoxidation of olefins with H2O2 was performed with a tungsten-containi ng catalyst. This insoluble catalyst forms soluble active species by the ac tion of H2O2, and when the H2O2 is used up, the catalyst precipitates for e asy recycling. Thus, the advantages of both homogeneous and heterogeneous c atalysts are combined in one system through reaction-controlled phase trans fer of the catalyst. When coupled with the 2-ethylanthraquinone/2-ethylanth rahydroquinone redox process for H2O2 production, O-2 can be used for the e poxidation of propylene to propylene oxide with 85% yield based on 2-ethyla nthrahydroquinone without any co-produds. This approach avoids the problema tic co-products normally associated with the industrial production of propy lene oxide.