Hydrogenation of unsaturated ketones: selective catalytic transfer hydrogenation of 5-hexen-2-one over MgO

Abstract

In the present study the selective catalytic transfer hydrogenation of an unsaturated ketone is described. During the heterogeneous catalytic transfer hydrogenation of 5-hexen-2-one with 2-propanol to 5-hexen-2-ol on MgO, the catalyst was continuously poisoned, which lead to a complete loss of activity. The major point of the present work is that the deactivation can be prevented by treatment with chloromethanes. The best results were obtained on MgO previously treated with chloroform. As a result the selectivity of the formation of 5-hexen-2-ol was close to 100% and no catalyst deactivation was observed during the time period studied. Detailed investigations were carried out (MgO treatment with different organochlorine reagents, FT-IR spectroscopy, CDCl3 adsorption, reaction of chloromethanes with MgO in pulse system) in order to optimize the reaction conditions and to certify the mechanism proposed earlier.