764-93-2Relevant articles and documents
Synthesis of acetylenes via dehydrobromination using solid anhydrous potassium phosphate as the base under phase-transfer conditions
Shenawi-Khalil, Sanaa,Sonavane, Sachin U.,Sasson, Yoel
experimental part, p. 2295 - 2297 (2012/07/27)
Phase-transfer catalyzed preparation of acetylenes from the corresponding vicinal dibromo compounds via double dehydrobromination using the mild solid base, anhydrous potassium phosphate, under very mild conditions is reported.
Weakly nucleophilic conjugate bases of superacids as powerful nucleophiles in vinylic bimolecular nucleophilic substitutions of simple β- alkylvinyl(aryl)-λ3-bromanes
Ochiai, Masahito,Okubo, Takuji,Miyamoto, Kazunori
, p. 3342 - 3344 (2011/05/04)
We report herein, for the first time, the stereoselective synthesis of simple (E)-β-alkylvinyl(aryl)-λ3-bromanes via a boron-λ3-bromane exchange reaction and their unique bimolecular nucleophilic substitutions at the vinylic ipso carbon atom under mild conditions. Interestingly, even weakly nucleophilic anions such as conjugate bases of superacids (HBF4, TfOH, Tf2CH 2, Tf3CH, Tf2NH, etc.) function as nucleophiles toward the vinyl-λ3-bromanes. For instance, the vinylic SN2 reaction of (E)-vinyl-λ3-bromanes with potassium bis(triflyl)methanide stereoselectively produced (Z)-vinyloxy oxosulfonium ylides with exclusive inversion of configuration via oxygen attack, while that with potassium bis(triflyl)imide afforded predominantly (Z)-vinyloxysulfoximines. In marked contrast, (E)-β-alkylvinyl- λ3-iodanes do not undergo the vinylic SN2 reaction with these conjugate bases of superacids. The differences between the nucleofugalities of aryl-λ3-iodanyl and aryl- λ3-bromanyl groups (the latter being greater) probably play a pivotal role in these unique reactions.
Nucleophilic vinylic substitutions of (Z)-(2-aroyloxyvinyl)phenyl- λ3-iodanes with tetrabutylammonium halides: Vinylic S N2 reactions and ligand coupling on iodine(III)
Ochiai, Masahito,Nishi, Yoshio,Hirobe, Masaya
, p. 1863 - 1866 (2007/10/03)
Treatment of (Z)-(β-benzoyloxyvinyl)phenyl-λ3- iodanes, readily prepared from ethynyl(phenyl)(tetrafluoroborato)- λ3-iodane via stereoselective Michael-type addition of benzoic acids in methanol in the presence of sodium benzoates, with tetrabutylammonium halides in THF at 65°C results in a vinylic SN2 reaction to give the inverted (E)-β-benzoyloxyvinyl halides in high yields.
