Synthesis and characterization of new chiral octadentate nitrogen ligands and related copper(II) complexes as catalysts for stereoselective oxidation of catechols

Three new octadentate nitrogen ligands were employed for the synthesis of dinuclear and trinuclear copper(II) complexes. The complexes are active in the biomimetic oxidation of catechols to quinones and show stereoselective effects towards the optically active catechols l-Dopa and d-Dopa, and their methyl esters. In all cases, the preferred enantiomeric substrate has the l configuration.