The Catalytic Baeyer-Villiger Oxidation of Cyclohexanone to ε-Caprolactone over Stibium-containing Hydrotalcite

A series of hydrotalcite-like compounds were prepared under microwave irradiation, which were used to catalyze the Baeyer-Villiger oxidation of cyclohexanone to e-caprolactone with hydrogen peroxide as oxidant. The results show that stibium-containing hydrotalcite (Sb-HTL) has good catalytic properties in the reaction. In the Baeyer Villiger oxidation of cyclohexanone to epsilon-caprolactone with H2O2 catalyzed by Sb-HTL, the effects of reaction time, reaction temperature, amount of catalyst and H2O2/cyclohexanone molar ratio are also investigated in details. It is shown the cyclohexanone conversion and e-caprolactone selectivity can reach 79.15 and 93.84%, respectively, under the optimum reaction conditions. Furthermore, Sb-HTL can be reused for six times without obvious loss of activity and selectivity. Therefore, Sb-HTL is reusable and would be a promising catalyst for the Baeyer-Villiger oxidation using green and cheap oxidants like hydrogen peroxide instead of peroxycarboxylic acids.