Reaction-Controlled Phase Transfer Catalysis for Styrene Epoxidation to Styrene Oxide with Aqueous Hydrogen Peroxide

The epoxidation of styrene catalyzed by a reaction-controlled phase transfer catalyst [(C 18 H 37 (30%)+C 16 H 33 (70%))N(CH 3 ) 3 ] 3 [PW 4 O 16 ] with H 2 O 2 in a biphasic medium was investigated. Under certain conditions, the selectivity for styrene oxide was 95%, the conversion of styrene based on H 2 O 2 was 85%, and the reaction time was less than 1 h. During the reaction, this catalyst powder formed soluble active species by the action of H 2 O 2, was recovered as a precipitate, and was reused after H 2 O 2 was used up. After two times recycling, the catalyst kept almost the same activity.