- Synthesis of Aromatic Trifluoromethyl Compounds by Ring Expansion of Cyclodienes
-
Chlorotrifluoromethyl-1-diazirine was used for a source of chlorotrifluoromethyl carbene.The carbene added to cyclic dienes to give trifluoromethylated six-membered aromatic compounds.Thus, pyrrole gave 3-(trifluoromethyl)pyridine and cyclopentadiene gave benzotrifluoride.
- Kobayashi, Yoshiro,Nakano, Takaharu,Iwasaki, Hitomi,Kumadaki, Itsumaro
-
-
Read Online
- Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
-
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
-
supporting information
p. 15396 - 15405
(2021/10/12)
-
- Preparation method of 2-chloro-3-trifluoromethylpyridine
-
The invention discloses a preparation method of 2-chlorine- 3-trifluoromethylpyridine. The method comprises the following steps: (1), sequentially adding 2, 3, 6-trichloro-5-trifluoromethylpyridine, an acid-binding agent and a catalyst into a lower aliphatic alcohol solvent, and starting a circulating water pump to replace hydrogen in vacuum, with the addition amount of the catalyst being 0.01-0.5% of the reaction system; (2), controlling the temperature of the reductive dechlorination reaction to be -10-65 DEG C, the reaction hydrogen pressure to be 0.1-2.0 MPa and the reaction time to be 4-24 hours; and (3), filtering, rectifying and purifying the obtained reaction liquid in sequence to finish separation of corresponding products and unreacted raw materials. The preparation method of the2-chlorine-3-trifluoromethylpyridine, provided by the invention is simple in process, easy to operate and beneficial to industrial production, the obtained product is high in purity, the purity is greater than 98%, a plurality of useful products are produced at one time, and on the basis of the selectivity of the useful products, the selectivity is 95%, the conversion rate of a single raw material is over 95%, and the production cost is low.
- -
-
Paragraph 0029-0061
(2021/01/25)
-
- Tailorable carbazolyl cyanobenzene-based photocatalysts for visible light-induced reduction of aryl halides
-
Herein, a series of carbazolyl cyanobenzene (CCB)-based organic photocatalysts with a broad range of photoredox capabilities were designed and synthesized, allowing precise control of the photocatalytic reactivity for the controllable reduction of aryl halides via a metal-free process. The screened-out CCB (5CzBN), a metal-free, low-cost, scalable and sustainable photocatalyst with both strong oxidative and reductive ability, exhibits superior performance for both dehalogenation and C[sbnd]C bond-forming arylation reactions.
- Ou, Wei,Zou, Ru,Han, Mengting,Yu, Lei,Su, Chenliang
-
supporting information
p. 1899 - 1902
(2019/12/27)
-
- Au@ZnO Core-Shell: Scalable Photocatalytic Trifluoromethylation Using CF3CO2Na as an Inexpensive Reagent under Visible Light Irradiation
-
Trifluoromethylation is of significant importance for the synthesis of many small molecules vital for medicinal and agrochemical research. The importance of the CF3 group as well as the related synthetic challenges is so evident that many reagents have been reported for the synthesis of trifluoromethylated compounds, but these typical reagents are expensive and the methods for preparing them are difficult. Here, we report a new scalable and operationally simple trifluoromethylation reaction using sodium trifluoroacetate as a reagent and Au-modified ZnO as a photocatalyst under visible light irradiation. The reaction proceeds via trifluoromethylation of a broad range of aryl halides, arylboronic acids, and arene and heteroarene substrates. Some pharmaceutical and agrochemical compounds have been trifluoromethylated directly to demonstrate the applicability of the method.
- Bazyar, Zahra,Hosseini-Sarvari, Mona
-
supporting information
p. 2345 - 2353
(2019/10/16)
-
- Silica-supported silver nanoparticles as an efficient catalyst for aromatic C-H alkylation and fluoroalkylation
-
The efficient catalysis of oxidative alkylation and fluoroalkylation of aromatic C-H bonds is of paramount importance in the pharmaceutical and agrochemical industries, and requires the development of convenient Ag0-based nano-architectures with high catalytic activity and recyclability. We prepared Ag-doped silica nanoparticles (Ag0/+@SiO2) with a specific nano-architecture, where ultra-small sized silver cores are immersed in silica spheres, 40 nm in size. The nano-architecture provides an efficient electrochemical oxidation of Ag+@SiO2 without any external oxidant. In turn, Ag+@SiO2 5 mol% results in 100% conversion of arenes into their alkylated and fluoroalkylated derivatives in a single step at room temperature under nanoheterogeneous electrochemical conditions. Negligible oxidative leaching of silver from Ag0/+@SiO2 is recorded during the catalytic coupling of arenes with acetic, difluoroacetic and trifluoroacetic acids, which enables the good recyclability of the catalytic function of the Ag0/+@SiO2 nanostructure. The catalyst can be easily separated from the reaction mixture and reused a minimum of five times upon electrochemical regeneration. The use of the developed Ag0@SiO2 nano-architecture as a heterogeneous catalyst facilitates aromatic C-H bond substitution by alkyl and fluoroalkyl groups, which are privileged structural motifs in pharmaceuticals and agrochemicals.
- Khrizanforov, Mikhail N.,Fedorenko, Svetlana V.,Mustafina, Asiya R.,Kholin, Kirill V.,Nizameev, Irek R.,Strekalova, Sofia O.,Grinenko, Valeriya V.,Gryaznova, Tatiana V.,Zairov, Rustem R.,Mazzaro, Raffaello,Morandi, Vittorio,Vomiero, Alberto,Budnikova, Yulia H.
-
supporting information
p. 9608 - 9616
(2018/08/06)
-
- A radical approach to the copper oxidative addition problem: Trifluoromethylation of bromoarenes
-
Transition metal–catalyzed arene functionalization has been widely used for molecular synthesis over the past century. In this arena, copper catalysis has long been considered a privileged platform due to the propensity of high-valent copper to undergo reductive elimination with a wide variety of coupling fragments. However, the sluggish nature of oxidative addition has limited copper’s capacity to broadly facilitate haloarene coupling protocols. Here, we demonstrate that this copper oxidative addition problem can be overcome with an aryl radical–capture mechanism, wherein the aryl radical is generated through a silyl radical halogen abstraction. This strategy was applied to a general trifluoromethylation of aryl bromides through dual copper-photoredox catalysis. Mechanistic studies support the formation of an open-shell aryl species.
- Le, Chip,Chen, Tiffany Q.,Liang, Tao,Zhang, Patricia,MacMillan, David W. C.
-
p. 1010 - 1014
(2018/06/12)
-
- Diverse copper(iii) trifluoromethyl complexes with mono-, bi- and tridentate ligands and their versatile reactivity
-
Cu(iii) trifluoromethyl complexes are proposed as essential intermediates for many copper-promoted trifluoromethylation reactions, but remain elusive and scarcely explored. We report herein the isolation and spectroscopic and X-ray crystallographic charac
- Zhang, Song-Lin,Xiao, Chang,Wan, Hai-Xing
-
supporting information
p. 4779 - 4784
(2018/04/11)
-
- Method for synthesizing trifluoromethyl aromatic compounds
-
The invention aims to provide a method for converting arylamine into trifluoromethyl aromatic compounds under simple conditions. The trifluoromethyl aromatic compounds can be widely applied to the fields of pesticides, medicines, organic materials and the like. The method is characterized by comprising steps of (1), synthesizing Toni reagents alpha from sodium periodate, 2-iodobenzoic acid, acetic anhydride, cesium fluoride and Ruppert reagents; (2), dissolving the arylamine and hydrochloric acid in 1, 2-dichloroethane, stirring the arylamine, the hydrochloric acid and the 1, 2-dichloroethane for 5-10 min to obtain mixtures, adding tert-butyl nitrite into the mixtures under low-temperature conditions, carrying out stirring reaction for 30-60 min to obtain reaction products, adding tetrafluoroboric acid tetra-acetonitrile copper, the Toni reagents alpha and sodium bicarbonate into the reaction products and carrying micro-heat reaction for 10-20 hours; sequentially filtering, washing and drying reaction liquid after reaction is completely carried out and carrying out column chromatography separation and purification on the reaction liquid to obtain target products. The method has the advantage that the trifluoromethyl aromatic compounds can be widely applied to the fields of pesticides, medicines, organic materials and the like.
- -
-
Paragraph 0027; 0028
(2017/08/29)
-
- Copper-Promoted Conversion of Aromatic Amines into Trifluoromethylated Arenes: One-Pot Sandmeyer Trifluoromethylation
-
A simple copper-promoted one-pot Sandmeyer trifluoromethylation of aromatic amines with Langlois’ reagent has been demonstrated. The reaction is performed in mild reaction conditions under an air atmosphere with good substrate scope and functional group compatibility. It provides an alternative and straightforward synthetic approach to access a variety of trifluoromethylated arenes.
- Hong, Jianquan,Wang, Guifu,Huo, Lianguang,Zheng, Changge
-
supporting information
p. 1761 - 1767
(2017/09/06)
-
- C?H Bond Trifluoromethylation of Arenes Enabled by a Robust, High-Valent Nickel(IV) Complex
-
The robust, high-valent NiIV complex [(Py)2NiIVF2(CF3)2] (Py=pyridine) was synthesized and fully characterized by NMR spectroscopy, X-ray diffraction, and elemental analysis. It reacts with aromatic compounds at 25 °C to form the corresponding benzotrifluorides in nearly quantitative yield. The monomeric and dimeric NiIIICF3 complexes 2?Py and 2 were identified as key intermediates, and their structures were unambiguously determined by EPR spectroscopy and X-ray diffraction. Preliminary kinetic studies in combination with the isolation of reaction intermediates confirmed that the C?H bond-breaking/C?CF3 bond-forming sequence can occur both at NiIVCF3 and NiIIICF3 centers.
- D'Accriscio, Florian,Borja, Pilar,Saffon-Merceron, Nathalie,Fustier-Boutignon, Marie,Mézailles, Nicolas,Nebra, Noel
-
supporting information
p. 12898 - 12902
(2017/09/13)
-
- Trifluoromethylation of (hetero)aryl iodides and bromides with copper(i) chlorodifluoroacetate complexes
-
A new copper-mediated trifluoromethylation reaction using copper(i) chlorodifluoroacetate complexes as reagents is reported. The complex [L2Cu][O2CCF2Cl] (L = bpy, dmbpy, phen) reacted with (hetero)aryl iodides and bromides in the presence of CsF in DMF at 75 °C to afford the trifluoromethylarenes in good to excellent yields. High compatibility with various chemical functions or (hetero)cycles was also observed in the reaction. A reaction mechanism involving a difluorocarbene intermediate, along with a subsequent formation of a -CF3 anion was proposed.
- Lin, Xiaoxi,Li, Zhengyu,Han, Xiaoyan,Weng, Zhiqiang
-
p. 75465 - 75469
(2016/08/24)
-
- Isolation and characterization of copper(III) trifluoromethyl complexes and reactivity studies of aerobic trifluoromethylation of arylboronic acids
-
The isolation, characterization and reactivity of transition metal trifluoromethyl complexes are fundamental and challenging topics in trifluoromethylation chemistry. We report herein the synthesis and isolation of two new complexes [(phen)CuI(PPh3)2]+[CuIII(CF3)4]- (2) and (phen)CuIII(CF3)3 (3) as well as a known complex (bpy)CuIII(CF3)3 (4) at room temperature. 2 and 3 have been fully characterized using 1H, 19F, 31P NMR, elemental analyses and X-ray crystallography. Reactivity studies indicate that 2 is unreactive toward arylboronic acids. In contrast, 3 and 4 can react with various aryl and heteroaryl boronic acids to deliver trifluoromethylated arenes in good to quantitative yields under mild conditions. The presence of a fluoride additive in DMF under aerobic conditions is crucial to these reactions. This study provides fundamental information about the structure and reactivity of elusive Cu(iii) trifluoromethyl complexes that have been proposed as relevant reactive intermediates in many trifluoromethylation reactions.
- Zhang, Song-Lin,Bie, Wen-Feng
-
p. 70902 - 70906
(2016/08/05)
-
- Trifluoromethylation of arenediazonium salts with fluoroform-derived CuCF3 in aqueous media
-
A new protocol has been developed for trifluoromethylation of arenediazonium salts with moisture-sensitive CuCF3 (from fluoroform) in aqueous media. The reaction is governed by a radical mechanism, tolerates a broad variety of functional groups, and is applicable to the synthesis of complex, polyfunctionalized molecules. This journal is the Partner Organisations 2014.
- Lishchynskyi, Anton,Berthon, Guillaume,Grushin, Vladimir V.
-
supporting information
p. 10237 - 10240
(2014/08/18)
-
- Copper-mediated perfluoroalkylation of heteroaryl bromides with (phen)CuRF
-
The attachment of perfluoroalkyl groups onto organic compounds has been a major synthetic goal over the past several decades. Previously, our group reported phenanthroline-ligated perfluoroalkyl copper reagents, (phen)CuR F, which react with aryl iodides and aryl boronates to form the corresponding benzotrifluorides. Herein the perfluoroalkylation of a series of heteroaryl bromides with (phen)CuCF3 and (phen)CuCF 2CF3 is reported. The mild reaction conditions allow the process to tolerate many common functional groups. Perfluoroethylation with (phen)CuCF2CF3 occurs in somewhat higher yields than trifluoromethylation with (phen)CuCF3, creating a method to generate fluoroalkyl heteroarenes that are less accessible from trifluoroacetic acid derivatives.
- Mormino, Michael G.,Fier, Patrick S.,Hartwig, John F.
-
supporting information
p. 1744 - 1747
(2014/04/17)
-
- Conversion of aromatic amino into trifluoromethyl groups through a Sandmeyer-type transformation
-
A novel strategy for aromatic trifluoromethylation by converting amino into trifluoromethyl groups via a Sandmeyer-type reaction is reported. The transformation involves diazotization of the aromatic amines with tert-butyl nitrite and hydrochloric acid to form aryldiazonium chlorides, followed by trifluoromethylation with trifluoromethylsilver at low temperature. Various readily available aromatic amines are smoothly converted under mild conditions. Georg Thieme Verlag Stuttgart. New York.
- Wang, Xi,Xu, Yan,Zhou, Yujing,Zhang, Yan,Wang, Jianbo
-
supporting information
p. 2143 - 2148
(2014/08/18)
-
- Efficient copper-catalyzed trifluoromethylation of aromatic and heteroaromatic iodides: The beneficial anchoring effect of borates
-
Efficient copper-catalyzed trifluoromethylation of aromatic iodides was achieved with TMSCF3 in the presence of trimethylborate. The Lewis acid was used to anchor the in situ generated trifluoromethyl anion and suppress its rapid decomposition. Broad applicability of the new trifluoromethylating reaction was demonstrated in the functionalization of different aromatic and heteroaromatic iodides.
- Gonda, Zsombor,Kovacs, Szabolcs,Weber, Csaba,Gati, Tamas,Meszaros, Attila,Kotschy, Andras,Novak, Zoltan
-
supporting information
p. 4268 - 4271
(2014/09/30)
-
- DIRECT TRIFLUOROMETHYLATIONS USING TRIFLUOROMETHANE
-
A direct trifluoromethylation method preferably using a trifluoromethane as a fluoro-methylating species. In particular, the present method is used for preparing a trifluoromethylated substrate by reacting a fluoromethylatable substrate with a trifiuoromethylating agent in the presence of an alkoxide or metal salt of silazane under conditions sufficient to trifluoromethylate the substrate; wherein the fluoromethylatable substrate includes chlorosilanes, carbonyl compounds such as esters, aryl halides, aldehydes, ketones, chalcones, alkyl formates, alkyl halides, aryl halides, alkyl borates, carbon dioxide or sulfur.
- -
-
Paragraph 0049
(2014/03/25)
-
- Direct synthesis of a trifluoromethyl copper reagent from trifluoromethyl ketones: Application to trifluoromethylation
-
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
-
supporting information
p. 17692 - 17697
(2014/01/17)
-
- Trifluoromethylation of aryl and heteroaryl halides with fluoroform-derived CuCF3: Scope, limitations, and mechanistic features
-
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.
-
p. 11126 - 11146
(2013/12/04)
-
- Silver-mediated trifluoromethylation of aryldiazonium salts: Conversion of amino group into trifluoromethyl group
-
A novel strategy for aromatic trifluoromethylation by converting aromatic amino group into CF3 group is reported herein. This method, which can be considered as trifluoromethylation variation of the classic Sandmeyer reaction, uses readily available aromatic amines as starting materials and is performed under mild conditions.
- Wang, Xi,Xu, Yan,Mo, Fanyang,Ji, Guojing,Qiu, Di,Feng, Jiajie,Ye, Yuxuan,Zhang, Songnan,Zhang, Yan,Wang, Jianbo
-
supporting information
p. 10330 - 10333
(2013/08/23)
-
- CuI-mediated trifluoromethylations with stannanes. preliminary communication
-
(Trifluoromethyl)stannane reagents such as Bu3SnCF3 are effective in CuI-mediated trifluoromethylation reactions of aryl iodides. The reactions proceed via the intermediacy of [CuCF3] species.
- Sanhueza, Italo A.,Nielsen, Mads C.,Ottiger, Marcel,Schoenebeck, Franziska
-
p. 2231 - 2236
(2013/02/22)
-
- Me3SiCF3/AgF/Cu - A new reagents combination for selective trifluoromethylation of various organic halides by trifluoromethylcopper, CuCF3
-
An alternative copper halide-free route to obtain highly reactive trifluoromethylcopper species has been developed via the reaction of silver fluoride and trimethyl(trifluoromethyl)silane followed by a redox transmetallation with elemental copper. The composition of the reactive intermediate was investigated by means of UV/Vis/NIR, ESR, 19F NMR spectroscopy and ESI mass spectrometry. "Trifluoromethylcopper" prepared by the oxidative transmetallation route exhibits excellent reactivity and selectivity in substitutions of iodine or bromine bond to aromatic or heterocyclic compounds for trifluoromethyl groups without any additional catalyst.
- Kremlev, Mikhail M.,Mushta, Aleksej I.,Tyrra, Wieland,Yagupolskii, Yurii L.,Naumann, Dieter,M?ller, Angela
-
scheme or table
p. 67 - 71
(2012/03/10)
-
- FLUOROALKYLATION METHODS AND REAGENTS
-
A method of forming a fluorinated molecular entity includes reacting in a reaction mixture an aromatic halide, copper, a fluoroalkyl group, and a ligand. The aromatic halide includes an aromatic group and a halogen substituent bonded to the aromatic group. The ligand includes at least one group-V donor selected from phosphorus and an amine. The overall molar ratio of copper to aromatic halide in the reaction mixture is from 0.2 to 3. The method further includes forming a fluoroalkylarene including the aromatic group and the fluoroalkyl group bonded to the aromatic group. A composition, which may be used in the method, consists essentially of copper, the fluoroalkyl group, and the ligand, where the molar ratio of copper to the fluoroalkyl group is approximately 1.
- -
-
Page/Page column title page; 6; 28
(2012/03/11)
-
- A broadly applicable copper reagent for trifluoromethylations and perfluoroalkylations of aryl iodides and bromides
-
(Chemical Presented) Well compatible: The trifluoromethylations and perfluoroalkylations of aryl iodides and some aryl bromides with trifluoromethyl and perfluoroalkylcopper(I) phenanthroline complexes occur with broad scope at 25-50 8C (see scheme). The trifluoromethyl complex is prepared from inexpensive reagents and can be used in situ or isolated. The reactions tolerate a range of substituents and also occur with heteroaromatic systems.
- Morimoto, Hiroyuki,Tsubogo, Tetsu,Litvinas, Nichole D.,Hartwig, John F.
-
supporting information; experimental part
p. 3793 - 3798
(2011/05/15)
-
- Copper-catalyzed trifluoromethylation of aryl iodides with potassium (trifluoromethyl)trimethoxyborate
-
Potassium (trifluoromethyl)trimethoxyborate is introduced as a new source of CF3 nucleophiles in copper-catalyzed trifluoromethylation reactions. The crystalline salt is stable on storage, easy to handle, and can be obtained in near-quantitative yields simply by mixing B(OMe)3, CF3SiMe3, and KF. The trifluoromethylation reagent allows the conversion of various aryl iodides into the corresponding benzotrifluorides in high yields under mild, base-free conditions in the presence of catalytic quantities of a CuI/1,10-phenanthroline complex.
- Knauber, Thomas,Arikan, Fatih,Roeschenthaler, Gerd-Volker,Goossen, Lukas J.
-
experimental part
p. 2689 - 2697
(2011/04/15)
-
- Electrophilic trifluoromethylation of arenes and N-heteroarenes using hypervalent iodine reagents
-
The reaction of hypervalent iodine trifluoromethylating reagents with a variety of arenes and N-heteroarenes gives access to the corresponding trifluoromethylated compounds. In comparative studies, 1-trifluoromethyl-1,3- dihydro-3,3-dimethyl-1,2-benziodoxole (2) proved to be the superior to 1-trifluoromethyl-1,2-benziodoxol-3-(1H)-one (1) for the direct aromatic trifluoromethylation. Depending on the individual substrates, additives such as zinc bis(trifluoromethylsulfonyl)imide or tris(trimethylsilyl)silyl chloride proved helpful in promoting the reactions. In the case of nitrogen heterocycles a pronounced tendency for the incorporation of the trifluoromethyl group at the position adjacent to nitrogen was observed.
- Wiehn, Matthias S.,Vinogradova, Ekaterina V.,Togni, Antonio
-
experimental part
p. 951 - 957
(2010/10/02)
-
- Active trifluoromethylating agents from well-defined copper(I)-CF 3 complexes
-
The first examples of isolable and structurally characterized Cu(I)-CF3 complexes are reported. N-Heterocyclic carbene (NHC)-supported copper tert-butoxide complexes reacted with Me3Si-CF3 to afford new (NHC)Cu-CF3 complexes whose structures were dependent on whether or not the C4-C5 positions of the five-membered NHC rings were saturated. In situ generated (SIiPr)Cu-CF3 cleanly transferred its trifluoromethyl group to a number of organic halides under mild conditions. Copyright
- Dubinina, Galyna G.,Furutachi, Hideki,Vicic, David A.
-
supporting information; experimental part
p. 8600 - 8601
(2009/02/02)
-
- METHOD FOR PHOTOCHEMICAL HALOGENATION
-
The inventive method consists in adding an acid which removes hydrogen halide, especially HCI contained in a reaction mixture and makes it possible to carry out photochemical halogenation, especially chlorination of organic components by substituting hydrogen-chlorine, although initial components, target components or eventually present amines form, together with free hydrogen halide, for example HCI additive products which could form precipitate without acidification
- -
-
-
- Trifluoromethyl-substituted pyridines through displacement of iodine by in situ generated (trifluoromethyl)copper
-
A literature method reported for iodobenzene and congeners was successfully extended to the pyridine series. 2-Iodopyridines can be converted into 2-(trifluoromethyl)pyridines almost quantitatively. In contrast, yields are moderate at best if 3- and 4-iodopyridines or 2-bromopyridines are used as the starting materials. WILEY-VCH Verlag GmbH 2002.
- Cottet, Fabrice,Schlosser, Manfred
-
p. 327 - 330
(2007/10/03)
-
- Modified Ullmann coupling of 2-chloro-3-trifluoromethylpyridine
-
The application of the modified Ullmann reaction to 2-chloro-3-trifluoromethylpyridine furnishes 5,5'-bis(trifluoromethyl)-2,2'-bipyridine as the primary product, accompanied by small amounts of the expected 3,3'-bis(trifluoromethyl)-2,2'-bipyridine, 2-benzyl-3-(trifluoromethyl)pyridine, bibenzyl, 3-trifluoromethylpyridine, 3-methylpyridine, 2-hydroxyethyl-(3-trifluoromethylpyridyl) ether and 2-hydroxyethyl-(3-methylpyridyl) ether.For comparison purposes, a sample of 3,3'-bis-(trifluoromethyl)-2,2'-bipyridyl was prepared by the treatment of 2,2'-bipyridyl-3,3'-dicarboxylic acid with sulfur tetrafluoride.The formation of all but two compounds mentioned above can be rationalized on the basis of the single-electron-transfer process. - Keywords: Ullman coupling; Chlorotrifluoromethylpyridine; Bis(trifluoromethyl)bipyridine; Synthesis; NMR spectroscopy; Mass spectrometry
- Munavalli, S.,Rossman, D. I.,Szafraniec, L. L.,Beaudry, W. T.,Rohrbaugh, D. K.,et al.
-
-
- An Efficient Electrochemical Trifluoromethylation of Aromatic Halides with Bromotrifluoromethane and a Sacrificial Copper Anode
-
The electrochemical cross-coupling of bromotrifluoromethane with aromatic or heteroaromatic iodides and bromides is successfully achieved in a one-compartment electrolysis cell fitted with a sacrificial copper anode.
- Paratian, J. M.,Sibille, S.,Perichon, J.
-
-
- Reactions of Trifluoromethyl Bromide and Related Halides: Part 10. Perfluoroalkylation of Aromatic Compounds induced by Sulphur Dioxide Radical Anion Precursors
-
Perfluoroalkylation of electron-rich aromatic compounds with trifluoromethyl bromide, or long-chain perfluoroalkyl iodides, was performed in the presence of sodium dithionite or zinc-sulphur dioxide.This alkylation occurred at the ortho and para positions relative to the amino or hydroxy substitutent.Pyrroles were perfluoroalkylated regioselectively at the 2-position.This alkylation was interpreted as a radical aromatic substitution; the formation of the perfluoroalkyl radical can be induced by a single-electron transfer from sulphur dioxide radical anion to the perfluoroalkyl halide.
- Tordeux, Marc,Langlois, Bernard,Wakselman, Claude
-
p. 2293 - 2299
(2007/10/02)
-
- Halogenation of pyridine compounds
-
Side-chain fluorination of 3-methylpyridine is carried out by reaction with hydrogen fluoride and chlorine in the liquid phase. The main products are 3-trifluoromethylpyridine, 3-chlorodifluoropyridine and 3-difluoromethylpyridine.
- -
-
-
- Studies on Organic Fluorine Compounds. Part 27. Abnormal Reactions in the Trifluoromethylation of Aromatic Compounds with Trifluoromethyl Iodide and Copper Powder
-
Reaction of 3-bromobenzofuran with trifluoromethyl iodide and copper powder in pyridine gave 2-(trifluoromethyl)-, 2- and 3-(pentafluoroethyl)-, and 2,3-bis(trifluoromethyl)-benzofuran, as well as the expected product, 3-(trifluoromethyl)benzofuran.Bromoanisole also gave (trifluoromethyl)anisole and (pentafluoroethyl)anisole, but introduction of the perfluoroalkyl group occurred at the position originally occupied by the bromine.Formation of pentafluoroethyl compounds is explained by decomposition of trifluoromethylcopper to cuprous fluoride and difluorocarbene, which can then react with a further molecule of trifluoromethylcopper to form pentafluoroethylcopper.This then reacts with aryl halide to give pentafluoroethyl compounds.Perfluoroalkylcopper is thermally cleaved to perfluoroalkyl radical, which then reacts with pyridine to give perfluoroalkylpyridines.This mechanism must be involved in the formation of 2,3-bis(trifluoromethyl)benzofuran.Introduction of a perfluoroalkyl group to the position originally unoccupied with halogen might be due to the rather localized double bond in benzofuran.
- Kobayashi, Yoshiro,Kumadaki, Itsumaro
-
p. 661 - 664
(2007/10/02)
-