Monomeric Cu(II) Complex Containing Chiral Phase-transfer Catalyst as Ligand and Its Asymmetrically Catalytic Reaction

The thermal treatment of CuCl₂ with N-(4′-vinylbenzyl)cinchonidinium chloride (L1) afforded a monomeric discrete homochiral copper(II) complex N-4′-(vinylbenzyl)cinchonidinium trichlorocoprate(II) (1). Their applications to the enantioselectively catalytic alkylation reaction of N-(diphenylmethylidene)glycine tert-butyl ester (3) show that the higher ee value observed in catalyst 1 than that in the corresponding free ligand L1 is probably due to the rigidity enhancement after the coordination of N atom of quinoline ring to the copper ion.