Sodium dithionite initiated addition of 1-bromo-1-chloro-2,2,2-trifluoroethane to allylaromatics

Selective fluoroalkylation of thiophenols by 1,2-dibromotetrafluoroethane activated by sulfur dioxide

“…Introduction of halocarbon fragments, containing other halogen atoms besides fluorine, into different organic substrates allows the synthesis of new polyfluoroalkyl substrates as well as transformation of fluorine containing substituents to more complex groups [1][2][3][4][5][6][7][8][9][10][11][12][13][14].…”

Sodium Dithionite

“…6 It was also found to be an efficient reagent for the reductive displacement of iodine 7 and reductive coupling of benzylic and allylic halides. 8 It has been also used as radical initiator to promote coupling of CF 3 CHClBr with 1,3,5-trimethoxybenzene, 9 the addition of 1-bromo-1-chloro-2,2,2-triuoroethane to the terminal double bond of allylbenzenes, 10 addition reaction of peruoroalkyl iodides with allenes, 11 the reaction of polyfluoroalkyl iodides with alkenes, 12 addition of dialkyl phosphonodifluoromethyl radical onto unsaturated ketones, 13 fluoroalkylation of porphyrins 14 and vinyl ethers. 15 This reagent is found to be a useful reagent in the intramolecular Marschalk cyclization 16 and Claisen rearrangement.…”

Sodium dithionite initiated fluoroalkylation of trimethoxybenzenes, mesitylene and pyrroles with BrCF2CF2Br

“…water-free dimethylsulphoxide, temperature of 75 8C and prolonged reaction time, perfluoroalkylation of N, S and O heteroaromatics and activated benzenes with long chain perfluoroalkyl chlorides has also been reported [8]. In our laboratory, it has been found that the Na 2 S 2 O 4 /acetonitrile/H 2 O system is also able to promote addition of polyhaloalkanes, i.e.1-bromo-1-chloro-2,2,2-trifluoroethane (Halothane 1 ) [9][10][11][12] and dibromodifluoromethane [13,14] to various electron-rich unsaturated compounds but most attempts to alkylate aromatic and heteroaromatic compounds with these reagents were unsuccessful. The only successful exceptions were reactions of 1-bromo-1-chloro-2,2,2-trifluoroethane with 1,3,5-trimethoxybenzene and with pyrroles, which resulted in coupling of one molecule of CF 3 CHClBr with two molecules of the aromatic compound to give, respectively, trifluoromethyl-bis(2,4,6-trimethoxyphenyl)methane [15] and 5-(trifluoromethyl)-dipyrromethanes [16] in a 38-50% yields.…”