Arynes as Radical Acceptors: TEMPO‐Mediated Cascades Comprising Addition, Cyclization, and Trapping

Abstract The application of arynes as radical acceptors is described. The stable radical TEMPO (2,2,6,6‐tetramethyl piperidine 1‐oxyl) is shown to add to various ortho‐substituted benzynes generating the corresponding aryl radicals which engage in 5‐exo or 6‐endo cyclizations. The cyclized radicals are eventually trapped by TEMPO. The introduced method provides ready access to various dihydrobenzofurans, oxindoles, and sultones by a conceptually novel approach.