Internal Delivery of Soft Chlorine and Bromine Atoms: Stereoselective Synthesis of (<i>E</i>)-β-Halogenovinyl(aryl)-λ³-iodanes through Domino λ³-Iodanation−1,4-Halogen Shift−Fluorination of Alkynes

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 tetrasubstituted β-halovinyl-λ3-iodanes with defined stereochemistry.