Simple Schiff-Base Cu(II) Complexes as Efficient Catalysts for Benzyl Alcohol Oxidation

Herein, we present synthesis and characterization of new ligand with N2O-donor moiety based on benzothiazole unit and its two complexes with Cu(II) cations. X-ray diffraction measurements revealed solid state structures of presented compounds as mono- and dinuclear entities. Both complexes appeared to be highly effective catalysts in oxidation process of benzyl alcohol and its derivatives in aqueous media. Copper(II)-(2,2,6,6-tetramethylpiperidine-1-oxyl) system provides selective conversion in the presence of 0.25 mol% and 1 mol% for complex 1 and 2, respectively. Obtained results revealed that both copper complexes are highly selective towards benzyl alcohols oxidation to its carbonyl analogues. It was tested in the presence of several electron donating and accepting substituents. Consequently, presented systems can provide effective catalytic oxidation of aforementioned groups in the presence of aliphatic alcohols.