Styrene epoxidation over a SBA-15-supported Mn(III) Schiff-base complex

Abstract

2,4-Di-tert-butyl-6-((E)-(propylimino)methyl)phenol as a Schiff-base ligand was immobilized onto an amino-functionalized SBA-15 through the reaction between di-tert-butyl-salicylaldahyde and the tethered amino group. The Mn(III) metal complex of the immobilized Schiff-base ligand was proven to be an active catalyst for the epoxidation of styrene withtert-butyl hydroperoxide as a terminal oxidant. The catalysts behaved as an oxidation catalyst in the epoxidation and could be used many times without structural degradation, leaching of active manganese species and significant activity loss. It has been concluded that the reversible redox cycles of the metal center play a key role during the epoxidation reaction, as well as in the reusability of the catalysts.