Catalytic highly enantioselective 1,3-dipolar cycloaddition reaction of nitrones with 3-alkenoyl-2-oxazolidinones by use of a bidentate chiral bis(imine) ligand-Cu(II) triflate complex

A copper(II) triflate complex with bidentate, chiral C-2-symmetric cyclohexane-1,2-bis[(2,6-dichlorophenylmethylene)amine] catalyzed the 1,3-dipolar cycloaddition reactions of nitrones with electron-deficient dipolarophiles, 3-(2-alkenoyl)-1,3oxazolidin-2-ones to give isoxazolidine cycloadducts with extremely high endo- and en antio selectivities. (C) 2004 Elsevier Ltd. All rights reserved.