- Efficient synthesis of unsymmetrical S-(bromodifluoromethyl)diarylsulfonium salts for electrophilic bromodifluoromethylating reagents
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A series of unsymmetrical S-(bromodifluoromethyl)diarylsulfonium salts 1 were readily synthesized by treatment of corresponding (bromodifluoromethyl) arylsulfoxides 2 and substituted benzenes 3 with triflic anhydride in moderate to good yields. The unsymmetrical sulfonium salts 1 with different aryl groups having electron-donating or electron-withdrawing substituents can be nicely constructed depending on the choice of 2 and 3. Bromodifluoromethylation of alkynes was evaluated by using the selected diarylsulfonium salts 1 to provide the desired bromodifluoromethylated alkynes in moderate to good yields.
- Liu, Guokai,Mori, Satoru,Wang, Xin,Noritake, Shun,Tokunaga, Etsuko,Shibata, Norio
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supporting information; experimental part
p. 1769 - 1773
(2012/10/08)
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- Sulfoximines as a versatile scaffold for electrophilic fluoroalkylating reagents
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New electrophilic fluoroalkylating agents based on the sulfoximine skeleton as a common platform are described. We demonstrate the importance of the activating group, attached to the nitrogen, and its specificity for the fluorinated group to be delivered.
- Urban, Celine,Cadoret, Frederic,Blazejewski, Jean-Claude,Magnier, Emmanuel
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experimental part
p. 4862 - 4867
(2011/10/09)
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- New electrophilic bromodifluoromethylation and pentafluoroethylation reagents
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S-(fluoroalkyl)diphenylsulfonium salts have been successfully synthesized from the reaction between fluoroalkylsul-finates and triflic anhydride in dichloromethane through a one-pot procedure. These S-(fluoroalkyl) diphenylsulfonium salts have been demonstrated to be effective reagents to fluoroalkylate C-nucleophilic substrates. Ionic substitution and radical or halogenophilic mechanism might be all involved in the reactions. Georg Thieme Verlag Stuttgart - New York.
- Zhang, Cheng-Pan,Cao, Hai-Ping,Wang, Zong-Ling,Zhang, Chun-Tao,Chen, Qing-Yun,Xiao, Ji-Chang
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supporting information; experimental part
p. 1089 - 1092
(2010/06/21)
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- An efficient synthesis of difluoropropargyl bromides
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High yields of γ-alkyl, -silyl and -aryl-substituted difluoropropargyl bromides have been obtained by monitoring concentration and temperature in the reaction between CF2Br2 and γ-substituted lithium acetylide. γ-Silyl substituents afforded the corresponding α,α,α-difluorobromopropargyl alcohols in good yields via cleavage of tetrabutylammonium fluoride in the presence of an aldehyde. Georg Thieme Verlag Stuttgart.
- Xu, Bo,Mae, Masayuki,Hong, Jiyoung A.,Li, Youhua,Hammond, Gerald B.
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p. 803 - 806
(2007/10/03)
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- Nucleophilic and electrophilic substitutions of difluoropropargyl bromides
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Fundamental organic reactions like nucleophilic and electrophilic substitutions have seldom been studied on fluorinated propargyl or allenyl modules, when the carbon atom undergoing substitution is bonded to two fluorine atoms. Herein we report a practical synthesis of difluoropropargyl bromides from substituted acetylenes and dibromodifluorometane using a wide variety of alkyl, aryl or silyl substrates. The synthesis of O-, S- and carboxylic acid derivatives of difluoropropargyl bromide is also described. These compounds are suitable starting materials for the synthesis of electrophilically substituted difluoropropargyl derivatives via magnesium and fluoride promoted reactions. An indium-mediated reaction of silyldifluoropropargyl bromide, followed by electrophilic trapping with bromine led to a very useful bromoallene, which was then used in reactions with nucleophiles (C, O, N, P, S, Hal) to yield a de facto bimolecular nucleophilic substitution of a difluoropropargyl bromide.
- Hammond, Gerald B.
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p. 476 - 488
(2008/03/14)
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- Reaction of CBrF2-CBrF2 with hydrazones of aromatic aldehydes. Novel efficient synthesis of fluorocontaining alkanes, alkenes and alkynes
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An olefination of hydrazones of aromatic aldehydes by CBrF2-CBrF2 under copper catalysis was investigated. In situ prepared aldehydes hydrazones were converted to (3-bromo-2,2,3,3-tetrafluoropropyl)arenes by reaction with CBrF2-CBrF2 in the presence of CuCl. Subsequent elimination of HF by sodium hydroxide resulted in stereospecific formation of fluorocontaining alkenes. Elimination proceeds stereoselectively, only Z -isomers of alkenes are formed. Elimination of two molecules of HF from (3-bromo-2,2,3,3-tetrafluoropropyl)arenes by treatment with potassium tert -butoxide leads to formation of (bromodifluoromethyl)alkynes. As a result a simple and efficient transformation of aromatic aldehydes to range of various fluorinated alkanes, alkenes and alkynes was elaborated.
- Nenajdenko, Valentine G.,Varseev, Georgy N.,Korotchenko, Vasily N.,Shastin, Alexey V.,Balenkova, Elisabeth S.
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p. 1339 - 1345
(2007/10/03)
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