Transition Metal Complexes of Schiff Base Ligands as Efficient Catalysts for Epoxidation of Alkenes
Chiral Schiff base complexes are highly selective in reactions such as epoxidation of alkenes. Transition metal complexes of Schiff bases possess high catalytic activity in comparison to their unsupported analogues. In the present study catalytic activity of metal complexes of different types of Schiff bases for epoxidation of alkenes was analyzed in this review. The Schiff base complexes of manganese(II) iron(II) cobalt(II) nickel(II) Chromium(III) and other ions are used as catalysts in the epoxidation. The manganese(III) Schiff base complexes exhibited high catalytic activity in the epoxidation of alkenes both in homogeneous and heterogeneous conditions. Polymer supported Schiff base complexes have demonstrated higher activity than unsupported Schiff base complexes of metal ions. The oxidation of styrene, indene, stilbene and its alkyl derivatives was catalyzed significantly by polymer supported Schiff base complexes of different metal ions. The recyclability of polymer supported Schiff base complexes is evaluated in this review.