313250-06-5Relevant academic research and scientific papers
The nucleophilic 5-endo-trig cyclization of 1,1-difluoro-1-alkenes: Ring-fluorinated hetero- and carbocycle synthesis and remarkable effect of the vinylic fluorines on the disfavored process
Ichikawa, Junji,Wada, Yukinori,Fujiwara, Masaki,Sakoda, Kotaro
, p. 1917 - 1936 (2007/10/03)
The disfavored 5-endo-trig cyclizations have been accomplished for 1,1-difluoro-1-alkenes with nitrogen, oxygen, sulfur, and carbon nucleophiles by taking advantage of the properties of fluorine. β,β-Difluorostyrenes bearing tosylamido, hydroxy, or methylsulfinyl group at the o-position undergo intramolecular nucleophilic substitution with a loss of the vinylic fluorine, leading to 2-fluorinated indole, benzo[b]furan, and benzo[b]thiophene in high yields, 1,1-Difluoro-1-butenes bearing homoallylic tosylamido, hydroxy, mercapto, or iodomethyl group also successfully cyclize via a 5-endo-trig process with the in situ generated intramolecular nucleophiles to afford 2-fluoro-2-pyrroline, 5-fluoro-2,3-dihydrofuran, 5-fluoro-2,3-dihydrothiophene, and 1-fluorocyclopentene. The two vinylic fluorines proved to be essential and play a critical role in these 'anti-Baldwin' cyclizations.
The nucleophilic 5-endo-trig cyclization of gem-difluoroolefins with homoallylic functional groups: Syntheses of ring-fluorinated dihydroheteroaromatics
Ichikawa,Fujiwara,Wada,Okauchi,Minami
, p. 1887 - 1888 (2007/10/03)
Gem-Difluoroolefins bearing homoallylic tosylamido, hydroxy, or mercapto groups undergo intramolecular nucleophilic substitution of the nitrogen, oxygen, or sulfur with loss of fluorine via a 5-endo-trig process, leading to 2-fluoro-2-pyrrolines, 5-fluoro
