OXIDATION AND EPOXIDATION OF HYDROCARBONS WITH O-2 CATALYZED BY EUCL3

Oxidation of cyclohexane and epoxidation of 1-hexene with O-2 by EuCl3 catalytic systems (EuCl3, Zn powder, carboxylic acid, and solvent) we re studied in detail. Combination of proton donors and solvents strong ly affected the turnover number (TON) and the selectivity of the monoo xygenation. The maximum TON of 11.7 in 1 h for oxidation of cyclohexan e to cyclohexanol and cyclohexanone (approximate to 100% total selecti vity) was obtained using acetic acid and dichloromethane at P(O-2) = 1 01 kPa and T = 40 degrees C. The selectivity to cyclohexanone increase d with increasing the yield for sum of the products. A successive reac tion of cyclohexanol to cyclohexanone became obvious at higher yields in oxidation of cyclohexane. In the case of epoxidation, the maximum T ON of the epoxide (81.4% selectivity) of 14.2 in 1 h was obtained usin g 1,2-dichloroethane and propionic acid at P(O-2) = 101 kPa and T = 40 degrees C. The selectivity to the epoxide did not change with the tot al yield. A successive reaction of 1,2-epoxyhexane to by-products was not observed in the oxidation of 1-hexene. A small amount of CO2 was p roduced from carboxylic acid, but none from the reactant. The efficien cy of Zn powder used to the monooxygenations was not more than 5%.