Reactions of some alkynyl halides with samarium(II) iodide

Article abstract of DOI:10.1016/0040-4020(95)00703-B

Certain alkynyl halides (6-halo-1-ynes) react with samarium(II) iodide (SmI₂) to give cyclized products (methylenecyclopentanes) in good yield. We have found some interesting evidence for the presence of radical and unstable organosamarium intermediates in these reductive cyclizations. Methyl 7-halohept-2-ynoates are not, however, good substrates for this cyclization methodology.