- Direct bromodeboronation of arylboronic acids with CuBr2 in water
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An efficient and practical method has been developed for the preparation of aryl bromides via the direct bromodeboronation of arylboronic acids with CuBr2 in water. This strategy provides several advantages, such as being ligand-free, base-free, high yielding, and functional group tolerant.
- Tang, Yan-Ling,Xia, Xian-Song,Gao, Jin-Chun,Li, Min-Xin,Mao, Ze-Wei
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supporting information
(2021/01/05)
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- Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
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In ample variety of transformations, the presence of silver as an additive or co-catalyst is believed to be innocuous for the efficiency of the operating metal catalyst. Even though Ag additives are required often as coupling partners, oxidants or halide scavengers, its role as a catalytically competent species is widely neglected in cross-coupling reactions. Most likely, this is due to the erroneously assumed incapacity of Ag to undergo 2e? redox steps. Definite proof is herein provided for the required elementary steps to accomplish the oxidative trifluoromethylation of arenes through AgI/AgIII redox catalysis (i. e. CEL coupling), namely: i) easy AgI/AgIII 2e? oxidation mediated by air; ii) bpy/phen ligation to AgIII; iii) boron-to-AgIII aryl transfer; and iv) ulterior reductive elimination of benzotrifluorides from an [aryl-AgIII-CF3] fragment. More precisely, an ultimate entry and full characterization of organosilver(III) compounds [K]+[AgIII(CF3)4]? (K-1), [(bpy)AgIII(CF3)3] (2) and [(phen)AgIII(CF3)3] (3), is described. The utility of 3 in cross-coupling has been showcased unambiguously, and a large variety of arylboron compounds was trifluoromethylated via [AgIII(aryl)(CF3)3]? intermediates. This work breaks with old stereotypes and misconceptions regarding the inability of Ag to undergo cross-coupling by itself.
- Demonti, Luca,Mézailles, Nicolas,Nebra, Noel,Saffon-Merceron, Nathalie
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supporting information
p. 15396 - 15405
(2021/10/12)
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- Synthesis method of 2-bromo-5-fluorobenzotrifluoride
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The invention relates to a synthesis method of 2-bromo-5-fluorobenzotrifluoride. The synthesis method comprises the following steps: with benzotrifluoride as a raw material, mixing benzotrifluoride with sulfuric acid, potassium bromide, cuprous bromide and a catalyst, and carrying out a bromination reaction to obtain 2-bromobenzotrifluoride; putting the obtained 2-bromobenzotrifluoride into a DMSOsolvent, adding potassium fluoride and KCoF4, and carrying out a fluorination reaction so as to obtain 2-bromo-5-fluorobenzotrifluoride. According to the method, trifluorotoluene is used as the raw material; the method is a brand-new synthetic route; bromination and fluorination conditions are mild; reaction yield is high; used raw materials are easy to purchase and low in price; and thus, the method has relatively high industrial application value.
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Paragraph 0025-0026; 0028-0029; 0031-0032; 0034-0035
(2020/07/15)
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- Cathodic C-H Trifluoromethylation of Arenes and Heteroarenes Enabled by an in Situ-Generated Triflyltriethylammonium Complex
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While several trifluoromethylation reactions involving the electrochemical generation of CF3 radicals via anodic oxidation have been reported, the alternative cathodic, reductive radical generation has remained elusive. Herein, the first cathodic trifluoromethylation of arenes and heteroarenes is reported. The method is based on the electrochemical reduction of an unstable triflyltriethylammonium complex generated in situ from inexpensive triflyl chloride and triethylamine, which produces CF3 radicals that are trapped by the arenes on the cathode surface.
- Cantillo, David,Jud, Wolfgang,Kappe, C. Oliver,Maljuric, Snjezana
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supporting information
(2019/10/08)
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- Visible-light-induced Pd-catalyzed: Ortho -trifluoromethylation of acetanilides with CF3SO2Na under ambient conditions in the absence of an external photocatalyst
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A visible-light-induced Pd-catalyzed ortho-trifluoromethylation of acetanilides with CF3SO2Na was developed. The reaction proceeded smoothly at room temperature in air without any external photocatalyst or additive, providing the desired products in moderate to good yields with good functional group tolerance and regioselectivity.
- Zou, Long,Li, Pinhua,Wang, Bin,Wang, Lei
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p. 3737 - 3740
(2019/04/01)
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- Visible-Light photoredox decarboxylation of perfluoroarene iodine(III) Trifluoroacetates for C-H trifluoromethylation of (Hetero)arenes
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A scalable and operationally simple decarboxylative trifluoromethylation of (hetero)arenes with easily accessible C6F5I(OCOCF3)2 under photoredox catalysis has been developed. This method is tolerant of various (hetero)arenes and functional groups. Notably, C6F5I is recycled from the decarboxylation reaction and further used for the preparation of C6F5I(OCOCF3)2. The combination of photoredox catalysis and hypervalent iodine reagent provides a practical approach for the application of trifluoroacetic acid in trifluoromethylation reactions.
- Yang, Bin,Yu, Donghai,Xu, Xiu-Hua,Qing, Feng-Ling
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p. 2839 - 2843
(2018/04/14)
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- Synthesis method of 2-bromo-5-fluorobenzotrifluoride
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The invention relates to a synthesis method of 2-bromo-5-fluorobenzotrifluoride, belonging to the field of chemical synthesis. The method uses orthotrifluoromethyl aniline as the initial raw material, and comprises the following steps: (1) Sandmeyer bromination reaction; (2) nitration reaction; (3) catalytic hydrogenation reduction reaction; and (4) diazotization fluorination reaction. According to the method, the orthotrifluoromethyl aniline used as the raw material is subjected to Sandmeyer reaction bromination, nitration, hydrogenation reduction and diazotization fluorination to finally synthesize the 2-bromo-5-fluorobenzotrifluoride. The 2-bromo-5-fluorobenzotrifluoride product has the advantages of high purity (up to 99.0% or above), fewer impurity varieties and stable quality and properties.
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Paragraph 0020
(2017/07/22)
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- Method for synthesizing 2-Bromobenzotrifluoride
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The present invention provides a method for synthesizing 2-Bromobenzotrifluoride, and the method comprises the following steps: A) 2-Aminotrifluoromethylbenzene, hydrobromic acid and sodium nitrite are mixed for reaction to obtain a diazonium salt solution; and B) the diazonium salt solution, cuprous bromide and hydrobromic acid are mixed for reaction to obtain the 2-Bromobenzotrifluoride. The method overcomes the defects of high cost, many product impurities and the like in prior art, cheap and accessible raw materials are used, solvent recovery effect is good, yield is high, product content is high, the 2-Bromobenzotrifluoride can be synthesized in one step, compared with other routes, meta and para isomers are less, and the production cost is low.
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Paragraph 0028; 0045-0048; 0052-0055; 0057-0060
(2017/08/27)
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- Introducing a new radical trifluoromethylation reagent
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Perfluoro-3-ethyl-2,4-dimethyl-3-pentyl radical (PPFR) is a persistent radical stable at room temperature, but easily decomposes at 90 °C to produce a CF3 radical which is able to react with a variety of aromatic compounds to afford the corresponding trifluoromethyl derivatives, usually as mixtures of regioisomers in good to excellent overall yields.
- Sato, Azusa,Han, Jianlin,Ono, Taizo,Wzorek, Alicja,Ace?a, José Luis,Soloshonok, Vadim A.
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supporting information
p. 5967 - 5970
(2015/03/30)
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- Direct synthesis of a trifluoromethyl copper reagent from trifluoromethyl ketones: Application to trifluoromethylation
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Being economic with fluorine: The direct synthesis of CuCF3 from a cuprate reagent and trifluoromethyl ketones, as one of the most economical and efficient trifluoromethyl sources, was accomplished. The advantages of this method are all of reagents employed are low-cost, operation is simple, and the yield of CuCF3 is virtually quantitative (see scheme). Furthermore, three types of trifluoromethylations smoothly proceeded to provide the corresponding products in high yields. Copyright
- Serizawa, Hiroki,Aikawa, Kohsuke,Mikami, Koichi
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supporting information
p. 17692 - 17697
(2014/01/17)
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- Trifluoromethylation of aryl and heteroaryl halides with fluoroform-derived CuCF3: Scope, limitations, and mechanistic features
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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.
- Lishchynskyi, Anton,Novikov, Maxim A.,Martin, Eddy,Escudero-Adan, Eduardo C.,Novak, Petr,Grushin, Vladimir V.
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p. 11126 - 11146
(2013/12/04)
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- Trifluoromethylation of 1-aryl-3,3-diisopropyltriazenes
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A new method for the trifluoromethylation of functionalized aromatic diisopropyltriazenes is described. In a facile two-step, one-pot synthesis, various functionalized trifluoromethyl-substituted arenes are accessible in mostly good yields by using methyl iodide as iodination agent and the trifluoromethylation system (trifluoromethyl)trimethylsilane/potassium fluoride/copper iodide. This concept could be expanded to perfluoroethylation as well as ethoxycarbonyldifluoromethylation reactions. Copyright
- Hafner, Andreas,Braese, Stefan
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supporting information
p. 996 - 1000
(2013/05/08)
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- Reactions of a 4-(Trifluoromethyl)thiazole Dianion
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Treatment of 2-trifluoroacetamido-4-(trifluoromethyl)thiazole with two equivalents of n-butyllithium at -78 deg C produced the thiazole dianion 5 in situ, which reacted preferentially at the 5-position with a variety of electrophiles.These electrophiles include: an aldehyde, ketone, chloroformate, acid chloride, phosphorus oxychloride, silicon chloride, and disulfide.Dianion 5 also combined with dibromodifluoromethane at -98 deg C to give the corresponding 5-(bromodifluoromethyl)thiazole 7, which is an unusual reaction for an aromatic or heteroaromatic system.Compound 7 was converted to a 4,5-bis-(trifluoromethyl)thiazole 8 using tetrabutylammonium fluoride.
- South, Michael S.,Sant, Karey A. Van
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p. 1017 - 1024
(2007/10/02)
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- TRIFLUORMETHYLIERUNGSREAKTIONEN VON Te(CF3)2 MIT HALOGENBENZOLEN UND METHYLBENZOLEN
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Substituent effects on yields and regioselectivity of photochemical and thermal trifluoromethylation reactions of Te(CF3)2 with halogen benzenes and methyl benzenes are investigated under comparable conditions.All reactions lead to trifluoromethylated products.The yields of the thermal are always higher than those of the corresponding photochemical reactions.The reactivity of the halobenzenes increases in the series C6H5-F a sidereaction, but H-substitution is the primary reaction pathway.During the reactions with iodobenzene tellurium containing compounds are also formed.The reactions with methyl benzenes show an increase in reactivity in the series hexamethylbenzene mesitylene toluene p-xylene.In all cases only ring substituted products are detected.Reactions with toluene and p-xylene yield tellurium containing compounds as well as addition products.The 19F-n.m.r spectra of the products are given.
- Naumann, Dieter,Kischkewitz, Jurgen
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p. 283 - 299
(2007/10/02)
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- Trifluoromethylbenzoyl bromide and conversion of same to bromobenzotrifluoride
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A novel compound, trifluoromethylbenzoyl bromide, is formed by bromination of trifluoromethylbenzoic acid with, e.g., phosphorus tribromide or by halogen exchange reaction of trifluoromethylbenzoyl chloride with bromine in the presence of a metal bromide. Decarbonylation of 2-, 3- or 4-trifluoromethylbenozyl bromide using a catalyst such as a phosphine-rhodium complex gives 2-, 3- or 4-bromobenzotrifluoride without forming isomers.
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- Photochemical Bromination of Simple Arenes
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Photochemical bromination of benzene, fluorobenzene, chlorobenzene, t-butylbenzene, α,α,α-trifluorotoluene, and (in tetrachloromethane) biphenyl and naphthalene gives substitution products and adducts such as 1,2,3,4,5,6-hexabromocyclohexane (1).The decomposition of (1) and of the analogous chlorobenzene adduct (3) under photochemical conditions gives the parent arene, the monobrominated halogenobenzene, and bromine which may be scavenged by toluene to give benzyl bromide or by benzene to give bromobenzene and dibromobenzenes.Addition is a kinetically controlled process, so that the mechanism of formation of these aryl bromides must be largely through the reversible formation of these adducts.This is consistent with the unusual orientation of apparent attack by bromine upon the arene substrates, since the relative amounts of the isomeric aryl bromides is a consequence of the relative stabilities and ease of elimination of HBr and Br2 from a family of adducts. The range of isomer distribution found within the reaction of each arene with bromine is consistent with two competing processes involved in the formation of the aryl bromides; one of these might by the direct homolytic substitution by bromine atoms upon the arene.
- Bolton, Roger,Bhangar, Muhammad Iqbal,Williams, Gareth H.
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p. 893 - 896
(2007/10/02)
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- FLUOROALKYLATION OF AROMATIC COMPOUNDS
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Perfluoroalkylation of benzene, halobenzenes, pyridine, furan and thiophene has been accomplished through thermolysis of perfluoroalkyl iodides (CF3I, n-C10F21I and RfORfI) in the presence of the appropriate aromatic compound.Yields of alkylated products vary depending on temperature, presence of an HI acceptor and reactants ratio.Isomeric mixtures are obtained with halobenzenes, pyridine and thiophene.Furan however yields only the alpha substituted product.
- Cowell, Allan B.,Tamborski, Christ
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p. 345 - 356
(2007/10/02)
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- A New Method for the Trifluoromethylation of Aromatics
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A new method is described for introducing a CF3-group, by a single-step synthesis, into aromatic compounds.This trifluoromethylation is done by means of a mixture consisting of HF/CCl4 and the aromatic compounds.The reaction is thought to be of a Friedel-Crafts type and limited to aromatics which are not substituted by electron withdrawing groups.
- Marhold, A.,Klauke, E.
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p. 281 - 292
(2007/10/02)
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