| Abstract
| - Bismuth(III) triflate was found to promote the formation of stable cyclic N-acyliminium species inremarkable catalytic amounts (1 mol %). The α-amidoalkylation process seems to be effective inintermolecular and intramolecular manners leading to α-substituted lactams and heterocyclic systemscontaining azacycles, respectively. By comparing our results with those obtained with the classical Lewisacids as catalysts, it was evidenced clearly that the use of bismuth(III) triflate had been efficient fornearly all α-acetoxy lactams we used, except for N-acyliminium precursors bearing a sulfur atom. Also,the process seems to be easy, general, and clean, having diastereoselectivity comparable to protocolsusing classical Lewis acids and resulting in the formation of polyheterocyclic systems in good to excellentyields (64−99% in acetonitrile as solvent).
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