Expeditious Approach to 5-Aroyl-pyrrolidinones by a Novel PIFA-Mediated Alkyne Amidation Reaction

[reaction: see text] A novel metal-free approach to the alkyne amidation reaction is presented. The oxidation of properly substituted amides by the hypervalent iodine reagent PIFA provides the generation of a nitrenium ion that can react intramolecularly with a triple bond, leading to the construction of the title compounds.