Environmentally friendly Baeyer-Villiger oxidation with H2O2/nitrile over Mg(OH)2 and MgO

We synthesized various magnesium hydroxides and calcined them to obtain oxides that were used as catalysts in the Baeyer-Villiger (BV) oxidation of cyclohexanone with a mixture of 30% aqueous hydrogen peroxide and benzonitrile as oxidant. The magnesium hydroxide obtained by precipitation from the nitrate was found to be the catalyst providing the highest conversion to ɛ-caprolactone and initial catalytic activity among all studied. Also, all hydroxides proved more active than their corresponding oxides in the BV reaction. The addition of an anionic surfactant had a favourable effect on the reaction that is explained by formulating a consistent mechanism. Finally, the influence of the variables involved in the process was examined in depth in order to bring the operating conditions as close as possible to those usable on an industrial scale.