Copper complexes bearing tridentate salicylaldimine Schiff-base ligands: Synthesis, characterizations and catalytic performance in the oxidation reaction of alcohols

Treatment of Cu(OAc)(2).H2O with salicylaldimine Schiff-base (C9H6N)N = CH(3,5-(Bu2C6H2OH)-Bu-t) (L1H), (Et2N) (CH2)(2)N = CH(3,5-(Bu2C6H2OH)-Bu-t) (L2H), (2-C5H4N)CH2N = CH(3,5-(Bu2C6H2OH)-Bu-t) (L3H) in refluxing ethanol afforded three mononuclear copper complexes [(L1)Cu(OAc)] (1), (L2)Cu(OAc) (2) and (L3)Cu(OAc) (3), respectively. The three new complexes were fully characterized using elemental analysis, IR and HR-MS, and Xray diffraction analysis. They all exhibited efficient catalytic activity in the oxidation of primary and secondary alcohols into the corresponding carbonyl derivatives with hydrogen peroxide (H2O2) as the oxidation agent. The catalytic system is operationally simple, clean and generates water as the only by-product.

Automated summary

Three new mononuclear copper complexes were obtained by treating Cu(OAc)(2).H2O with three different Schiff-base ligands. These complexes showed efficient catalytic activity in the oxidation of alcohols and water was the only by-product.