X = Cl, Br; n = 1-3 4-(Difluoroiodo)toluene-induced domino λ3-iodanation-1,4-halogen shift-ring enlargement-fluorination reaction of 5-halopentynes with a four-, five-, or six-membered carbocycle afforded the ring-expanded (E)-δ-fluoro-β-halovinyl- λ3-iodanes stereoselectively in high yields, probably via the intermediacy of five-membered halonium ions. Use of internal alkynes makes it possible to synthesize tetrasubstltuted β-halovinyl-λ3- iodanes with defined stereochemistry.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry