Reaction-Controlled Phase-Transfer Catalysis for Propylene Epoxidation to Propylene Oxide

The epoxidation of olefins with H 2 O 2 was performed with a tungsten-containing catalyst. This insoluble catalyst forms soluble active species by the action of H 2 O 2 , and when the H 2 O 2 is used up, the catalyst precipitates for easy recycling. Thus, the advantages of both homogeneous and heterogeneous catalysts are combined in one system through reaction-controlled phase transfer of the catalyst. When coupled with the 2-ethylanthraquinone/2-ethylanthrahydroquinone redox process for H 2 O 2 production, O 2 can be used for the epoxidation of propylene to propylene oxide with 85% yield based on 2-ethylanthrahydroquinone without any co-products. This approach avoids the problematic co-products normally associated with the industrial production of propylene oxide.