Schiff Base Based Metal Complexes: A Review of Their Catalytic Activity on Aldol and Henry Reaction

ABSTRACT Over the last few years, many Schiff base complexes of metal ions have exhibited substantial catalytic activity in various reactions such as oxidation, Henry reaction, hydroxylation, aldol condensation, and epoxidation. The literature survey shows that, over the past few years, there have been few reports on the catalytic aldol and Henry reaction where Schiff base-based metal complexes act as homogeneous or heterogeneous catalysis. This review reorganizes the various transition metal Schiff base complexes as well as chiral Schiff base metal complexes, which have potential application in catalytic activity on aldol and Henry reaction. Schiff bases are an important class of chelating ligands due to its coordination tendency and their complexes exhibit a wide range of applications in various fields like anti-bacterial, anti-fungal, antiviral, anti-cancer, antioxidant, anti-inflammatory, magnetism, luminescence, conductivity, sensing, catalytic, and so on. This review mainly focuses on the catalytic activities of Schiff base ligands and their transition metal complexes to the aldol and Henry reaction. GRAPHICAL ABSTRACT