Indium-mediated radical cyclization of iodoalkenes and iodoalkynes with and without allylic and propargylic leaving groups

Upon treatment with In and I₂, mono-substituted alkenes having an iodine substituent at the δ-position of the tether gave the corresponding iodinated cyclic compounds, whereas di- and tri-substituted alkenes gave the corresponding hydroxylated cyclic compounds. Alkenes bearing leaving groups at the allylic position were transformed only to the corresponding vinyl substituted cyclic compounds. On the other hand, alkynes bearing good leaving groups at the propargylic position gave allenic products selectively.