Junji Ichikawa, Yukinori Wada, Tatsuo Okauchi and Toru Minami
β,β-Difluorostyrenes bearing tosylamido, hydroxy ormethylsulfinyl groups at the o-position undergo intramol-ecular substitution of the nitrogen, oxygen or sulfur withloss of fluorine via a 5-endo-trigonal process leading to2-fluorinated heterocyclic systems in high yields.