Enamide-Benzyne-[2 + 2] Cycloaddition: Stereoselective Tandem [2 + 2]−Pericyclic Ring-Opening−Intramolecular N-Tethered [4 + 2] Cycloadditions

Benzyne-[2 + 2] cycloadditions with enamides are described. This effort led to the development of a highly stereoselective tandem [2 + 2] cycloaddition−pericyclic ring-opening−intramolecular-N-tethered-[4 + 2] cycloaddition for rapid assembly of nitrogen heterocycles.