Catalytic enantioselective [2+2]-cycloaddition reaction of 2-methoxycarbonyl-2-cyclopenten-1-one by chiral copper catalyst
摘要:
A new catalytic system for enantioselective [2+2]-cycloaddition reaction of 2-methoxycarbonyl-2-cyclopenten-1-one with thioacetylene derivatives is described. The use of a catalytic amount (20-30 mol%) of copper(II) salt with chiral bis-pyridine ligand was found to be effective in promoting the [2 + 2]-cycloaddition reaction, furnishing the corresponding bicyclic compound in good yield and good enantioselectivity. (c) 2006 Elsevier Ltd. All rights reserved.
(+)-tricycloclavulone having a unique tricyclo[5,3,0,01,4]decane skeleton and six chiral centers was achieved in a highly stereoselective manner. It includes a catalytic enantioselective [2+2]-cycloadditionreaction using novel chiral copper catalyst, extremely effecting an intramolecular ester transfer reaction, and asymmetric reduction of the carbonyl group on the alpha-chain using Noyori's chiral ruthenium catalyst
A new catalytic system for enantioselective [2+2]-cycloaddition reaction of 2-methoxycarbonyl-2-cyclopenten-1-one with thioacetylene derivatives is described. The use of a catalytic amount (20-30 mol%) of copper(II) salt with chiral bis-pyridine ligand was found to be effective in promoting the [2 + 2]-cycloaddition reaction, furnishing the corresponding bicyclic compound in good yield and good enantioselectivity. (c) 2006 Elsevier Ltd. All rights reserved.