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.
Keywords: TEMPO; arynes; cyclization; heterocycles; radicals.
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