Sustainable and Practical Access to Epoxides: Metal-Free Aerobic Epoxidation of Olefins Mediated by Peroxy Radical Generated In Situ

A sustainable and practical protocol to prepare epoxides has been established by using air as the oxidant in the presence of K2CO3 in isopropylbenzene (CM) at 80-140 degrees C. The olefins are successfully converted into their corresponding epoxides in yields of up to 99%. CM and K2CO3 are reused in the scale-up recycling experiments. A reaction mechanism dominated by the radical pathway is proposed according to the control experiments and kinetic analysis.