195734-33-9Relevant articles and documents
Silver-catalyzed vinylic C-F bond activation: Synthesis of 2-fluoroindoles from β,β-difluoro-o-sulfonamidostyrenes
Fujita, Takeshi,Watabe, Yota,Yamashita, Shigeyuki,Tanabe, Hiroyuki,Nojima, Tomoya,Ichikawa, Junji
supporting information, p. 964 - 966 (2016/08/13)
An electrophilic 5-endo-trig cyclization of β,β-difluoro-o-sulfonamidostyrenes was performed in 1,1,1,3,3,3-hexafluoropropan-2-ol using a Ag(I) catalyst and N,O-bis(trimethylsilyl)acetamide. In this process, vinylic C-F bond activation was achieved via silver-catalyzed β-fluorine elimination, accompanied by C-N bond formation, which led to the synthesis of 2-fluoroindoles.
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.
