Alkylidenecarbene insertion into a nitrogen lone pair: An unexpected synthesis of dihydropyrroles from alkynyliodonium salts

A novel intramolecular reaction between an alkylidenecarbene and the lone p air of electrons on a carbamate's nitrogen is described. The reaction occur s preferentially over an available 1,5 C-H insertion and gives substituted dihydropyrroles upon workup.