Copper-catalyzed facile carbon-carbon bond forming reactions at the α-position of α,α,γ-trichlorinated γ-lactams

Treatment of a,alpha,alpha,gamma-trichlorinated gamma-lactams with a catalytic amount of CuCl(bipyridine) complex resulted in facile activation of their carbon-chlorine bond at the alpha-position. Addition of the carbon moiety and the chlorine atom to olefins furnished the carbon-carbon bond forming reaction at the alpha-position of the carbonyl group. In certain trichlorinated gamma-lactams including a carbon-carbon double bond at an appropriate position, intramolecular addition reactions took place to give bicyclic lactams. Sequential reactions consisting of the cyclization of N-allyl trichloroacetamides followed by the inter- or intramolecular carbon-carbon bond forming reactions at the alpha-position of the lactams were also achieved. Efficiency of the catalyst and reaction rate was dependent on the protecting group of the nitrogen atom of the gamma-lactams; N-tosyl derivatives gave better results than the corresponding N-benzyl homologues. The molecular structure of the representative products revealed the stereochemical outcome of the reactions. (C) 1999 Elsevier Science Ltd. All rights reserved.