The nucleophilic 5-endo-trig cyclization of gem-difluoroolefins with homoallylic functional groups: syntheses of ring-fluorinated dihydroheteroaromatics
J. Ichikawa et al., The nucleophilic 5-endo-trig cyclization of gem-difluoroolefins with homoallylic functional groups: syntheses of ring-fluorinated dihydroheteroaromatics, CHEM COMMUN, (19), 2000, pp. 1887-1888
gem-Difluoroolefins bearing homoallylic tosylamido, hydroxy, or mercapto gr
oups undergo intramolecular nucleophilic substitution of the nitrogen, oxyg
en, or sulfur with loss of fluorine via a 5-endo-trig process, leading to 2
-fluoro-2-pyrrolines, 5-fluoro-2,3-dihydrofurans, or -thiophenes in high yi
elds.