Magnesium oxide-supported polytitazane cobalt(III) complex for catalytic epoxidation of ?-pinene with molecular oxygen

Abstract

Magnesium oxide-supported polytitazane cobalt complex has been prepared and found to be a very effective catalyst for the epoxidation of α-pinene in the presence of an aldehyde as a reductant. XPS data show that the high valent cobalt(III) was stabilized by the mutidentate nitrogen ligand of polytitazane. The α-pinene oxide can be obtained in 96.0% yield with 96.6% selectivity at 25°C under an atmospheric pressure of molecular oxygen. Isobutyraldehyde is an effective reductant and only 1.2 equivalent of isobutyraldehyde to α-pinene is needed to ensure high yield of α-pinene oxide. The catalyst is also very stable and can be reused at least eight times without loss of its activity.