A recyclable hybrid manganese(III) porphyrin magnetic catalyst for selective olefin epoxidation using molecular oxygen

The synthesis and characterization of a hybrid Mn(III)-porphyrin magnetic nanocomposite is described. Moreover, a sustainable methodology for epoxidation of olefins is reported, using O-2 as a green oxidant and the magnetic nanoparticle as a recyclable catalyst. High activity in alkene oxidation was observed, with full selectivity for epoxide formation. The magnetic catalyst presented high stability, being recovered and reused in five consecutive runs without loss of catalytic activity or selectivity in cyclooctene oxidation. Moreover, the catalytic system showed very good reactivity toward epoxidation of a range of terminal, substituted, cyclic or acyclic, aliphatic and aromatic olefins, including terpene and steroid derivatives, affording a range of biologically relevant epoxides in excellent yields. The isobutyric acid, formed as side-product, was recovered with high yield and purity, which provides the potential reutilization of this important industrial product.