Chiral copper(II) complexes of optically active Schiff bases: syntheses, crystal structure and asymmetric oxidation of methyl phenyl sulfide with hydrogen peroxide

Several chiral copper(II) complexes of optically active Schiff bases (R,R)-4a-c, which have central seven-membered chelate rings, have been synthesized and characterized. X-ray single crystal analysis of a typical compound indicated that the complex is monomeric and the geometry around the metal atom is very distorted tetrahedral. All the complexes have been tested as catalysts for asymmetric oxidation of methyl phenyl sulfide. The mechanism of the catalytic reaction in the presence of these complexes has been tentatively elucidated. (C) 2004 Elsevier Ltd. All rights reserved.