One-step synthesis of propylene oxide catalysed by the EuCl3-O2-Zn-MeCO2H-system

Epoxidation of propylene to propylene oxide with O-2 catalysed by the EuCl3-system was studied at atmospheric and under pressure conditions at 30 degrees C. Active oxygen species generated in the EuCl3-catalytic system is an oxidant powerful enough to be able to epoxidize simple alkenes, propylene and hexenes at atmospheric pressure, but is not favourable for the epoxidation of reactive alkenes, stylbene and cyclohexene. Fairly good yield and the selectivity to propylene oxide (17.1 TON (turnover number), 3.3% yield (C3H6), 94% selectivity) were obtained under pressure conditions (C3H6 10 atm and O-2 4 atm) at 30 degrees C. A high concentration of EuCl3-catalyst is not good for selective formation of propylene oxide. The active oxygen species generated in the EuCl3-system has the double character of radical property and electrophilicity that could not be obtained from H2O2 and Eu3+. (C) 1998 Elsevier Science B.V. All rights reserved.