1620-79-7Relevant articles and documents
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Janz,de Crescente
, p. 765 (1958)
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Deoxofluorination of (Hetero)aromatic Acids
Alekseenko, Anatoliy N.,Bugera, Maksym Ya.,Gerus, Igor I.,Kiriakov, Oleksandr,Klipkov, Anton A.,Mykhailiuk, Pavel K.,Pustovit, Yurii,Razhyk, Bohdan,Semenov, Sergey,Starova, Viktoriia S.,Tananaiko, Oksana Yu.,Tarasenko, Karen,Tolmachev, Andrei A.,Trofymchuk, Serhii,Zaporozhets, Olga A.
, p. 3110 - 3124 (2020/03/23)
Diverse trifluoromethyl-substituted compounds were synthesized by deoxofluorination of cinnamic and (hetero)aromatic carboxylic acids with sulfur tetrafluoride. The obtained products were used as starting materials in the preparation of novel fluorinated amino acids, anilines, and aliphatic amines - valuable building blocks for medicinal chemistry and agrochemistry.
Trifluoromethylation of aryl and heteroaryl halides with fluoroform-derived CuCF3: Scope, limitations, and mechanistic features
Lishchynskyi, Anton,Novikov, Maxim A.,Martin, Eddy,Escudero-Adan, Eduardo C.,Novak, Petr,Grushin, Vladimir V.
, p. 11126 - 11146 (2013/12/04)
Fluoroform-derived CuCF3 recently discovered in our group exhibits remarkably high reactivity toward aryl and heteroaryl halides, performing best in the absence of extra ligands. A broad variety of iodoarenes undergo smooth trifluoromethylation with the ligandless CuCF3 at 23-50 C to give the corresponding benzotrifluorides in nearly quantitative yield. A number of much less reactive aromatic bromides also have been trifluoromethylated, including pyridine, pyrimidine, pyrazine, and thiazole derivatives as well as aryl bromides bearing electron-withdrawing groups and/or ortho substituents. Only the most electrophilic chloroarenes can be trifluoromethylated, e.g., 2-chloronicotinic acid. Exceptionally high chemoselectivity of the reactions (no side-formation of arenes, biaryls, and C2F5 derivatives) has allowed for the isolation of a large number of trifluoromethylated products in high yield on a gram scale (up to 20 mmol). The CuCF3 reagent is destabilized by CuX coproduced in the reaction, the magnitude of the effect paralleling the Lewis acidity of CuX: CuCl > CuBr > CuI. While SNAr and SRN1 mechanisms are not operational, there is a well-pronounced ortho effect, i.e., the enhanced reactivity of ortho-substituted aryl halides 2-RC6H4X toward CuCF3. Intriguingly, this ortho-effect is observed for R = NO2, COOH, CHO, COOEt, COCH3, OCH3, and even CH3, but not for R = CN. The fluoroform-derived CuCF3 reagent and its reactions with haloarenes provide an unmatched combination of reactivity, selectivity, and low cost.