Intramolecular Benzyne–Phenolate [4+2] Cycloadditions

Abstract An intramolecular benzyne–phenolate [4+2] cycloaddition is reported. Benzyne precursors, having vicinal halogen‐sulfonate functionalities, linked with a phenol(ate) by various tether groups undergo efficient intramolecular [4+2] cycloaddition by treatment with either Ph 3 MgLi or n BuLi for halogen–metal exchange to form various benzobarrelenes.