Intramolecular carbon-hydrogen insertion reactions of carbenes have proven to be powerful and invaluable tools in the synthesis of highly functionalized, five-membered ring systems.* We report herein a novel and potentially highly versatile cyclopentene annulation utilizing hypervalent organoiodine (II1) compounds, alkynyliodonium salts, via the tandem Michael- carbene insertion (MCI) reaction (Scheme I).
