A Novel and Regioselective Radical Cyclization of gem-Dihalocyclopropyl Substituted Alkenes and Alkynes Using Tributyltin Hydride and Catalytic AIBN

Various gem-dihalocyclopropyl substituted alkenes and alkynes were transformed into the corresponding bicyclo[3.1.0]- or [4.1.0] compounds with high regioselectivity through a reductive radical cyclization using tributyltin hydride in the presence of catalytic azobisisobutyronitrile (AIBN).