Bismuth (III) triflate was found to promote the formation of stable cyclic N-acyliminium species in remarkable catalytic amounts (1 mol%). The α-amidoalkylation process seems to be effective in intermolecular and intramolecular manners leading to α-substituted lactams and heterocyclic systems containing azacycles, respectively. By comparing our results with those obtained with the classical Lewis acids as catalysts, it was evidenced clearly that the ...