- Mechanistic study of visible light-driven CdS or g-C3N4-catalyzed C–H direct trifluoromethylation of (hetero)arenes using CF3SO2Na as the trifluoromethyl source
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The mild and sustainable methods for C–H direct trifluoromethylation of (hetero)arenes without any base or strong oxidants are in extremely high demand. Here, we report that the photo-generated electron-hole pairs of classical semiconductors (CdS or g-C3N4) under visible light excitation are effective to drive C–H trifluoromethylation of (hetero)arenes with stable and inexpensive CF3SO2Na as the trifluoromethyl (TFM) source via radical pathway. Either CdS or g-C3N4 propagated reaction can efficiently transform CF3SO2Na to [rad]CF3 radical and further afford the desired benzotrifluoride derivatives in moderate to good yields. After visible light initiated photocatalytic process, the key elements (such as F, S and C) derived from the starting TFM source of CF3SO2Na exhibited differential chemical forms as compared to those in other oxidative reactions. The photogenerated electron was trapped by chemisorbed O2 on photocatalysts to form superoxide radical anion (O2[rad]?) which will further attack [rad]CF3 radical with the generation of inorganic product F? and CO2. This resulted in a low utilization efficiency of [rad]CF3 (3SO2Na served as the starting materials in inert atmosphere, the photoexcited electrons can be directed to reduce the nitro group to amino group rather than being trapped by O2. Meanwhile, the photogenerated holes oxidize SO2CF3? into [rad]CF3. Both the photogenerated electrons and holes were engaged in reductive and oxidative paths, respectively. The desired product, trifluoromethylated aniline, was obtained successfully via one-pot free-radical synthesis.
- Fu, Xianzhi,Gao, Li,Liu, Ming,Lu, Chenggang,Ma, Xiongfeng,Qin, Nanfang,Qiu, Wenzhao,Sa, Rongjian,Wang, Lele,Wei, Yingcong,Xu, Chunwang,Yuan, Rusheng,Zha, Wenying
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- Ruthenium-Catalyzed Site-Selective Trifluoromethylations and (Per)Fluoroalkylations of Anilines and Indoles
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Introducing (per)fluoroalkyl groups into arenes continues to be an interesting, but challenging area in organofluorine chemistry. We herein report an ortho-selective C?H perfluoroalkylation including trifluoromethylations of anilines and indoles without the need of protecting groups using RfI and RfBr as commercially available reagents. The availability and price of the starting materials and the inherent selectivity make this novel methodology attractive for the synthesis of diverse (per)fluoroalkylated building blocks, for example, for bioactive compounds and materials.
- Li, Yang,Neumann, Helfried,Beller, Matthias
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supporting information
p. 6784 - 6788
(2020/05/18)
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- Transition metal-free direct C–H trifluoromethyltion of (hetero)arenes with Togni's reagent
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A new transition-metal-free direct C–H trifluoromethylation reaction of (hetero)arenes with Togni's reagent was developed. This transformation proceeded smoothly under mild conditions and exhibited good tolerance of many synthetically relevant functional groups. It provided an alternative approach for the synthesis of trifluoromethylated (hetero)arenes.
- Chen, Xiaoyu,Ding, Licheng,Li, Linlin,Li, Jingya,Zou, Dapeng,Wu, Yangjie,Wu, Yusheng
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supporting information
(2019/12/30)
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- Preparation method of trifluoromethylated aniline compound
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The invention provides a preparation method of a trifluoromethylated aniline compound shown in a formula (IIA) or a formula (IIB). The method comprises the following steps: by taking a mixed solvent of DMF and water in a volume ratio of 1:(1-4) as a reaction medium, adding an aniline compound shown in a formula (IA) or a formula (IB), 1-(trifluoromethyl)-1,2-benziodoxol-3-(1H)-one and a photocatalyst, and reacting for 2-6 hours at room temperature under blue light; and carrying out post-treatment on the obtained reaction mixture to obtain the trifluoromethylated aniline compound as shown in the formula (IIA) or the formula (IIB). According to the method, by the photocatalyst, the reaction is driven to be carried out under the irradiation of visible light, the reaction conditions are mild,the site selectivity is high, the reaction is efficient, green and environment-friendly, the reaction yield can reach 90%, and the product can be prepared by only one step.
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Paragraph 0069-0077
(2020/12/30)
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- Coordinating Activation Strategy-Induced Selective C?H Trifluoromethylation of Anilines
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A simple protocol for the synthesis of 2-(trifluoromethyl)aniline derivatives through a coordinating activation strategy was developed. The reaction showed good reactivity and gave the target products in moderate to good yields. Pleasingly, the directing group could be recovered in excellent yield. Furthermore, this strategy allowed efficient access to the synthesis of floctafenine. A single-electron-transfer mechanism was proposed to be responsible for this trifluoromethylation reaction.
- Xu, Jun,Cheng, Ke,Shen, Chao,Bai, Renren,Xie, Yuanyuan,Zhang, Pengfei
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p. 965 - 970
(2018/02/12)
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- Nickel-Catalyzed Direct C-H Trifluoromethylation of Free Anilines with Togni's Reagent
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An efficient nickel-catalyzed C-H trifluoromethylation for the synthesis of trifluoromethylated free anilines using Togni's reagent has been developed. This approach exhibits a good functional group tolerance, good regioselectivity, and chemoselectivity under mild conditions. The newly developed economical one-step method is a better alternative to synthesize trifluoromethylated free anilines.
- Gao, Xianying,Geng, Yang,Han, Shuaijun,Liang, Apeng,Li, Jingya,Zou, Dapeng,Wu, Yusheng,Wu, Yangjie
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supporting information
p. 3732 - 3735
(2018/07/22)
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- Preparation method of trifluoromethylamine
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The invention relates to a preparation method of trifluoromethylamine. The method includes the following steps that aromatic amine shown in the formula (1) and a trifluoromethyl reagent shown in the formula (2) react in a solvent under the condition that an alkali and/or nickel compound exists, and the trifluoromethylamine compound shown in the formula (3) is generated. According to the preparation method of trifluoromethylamine, aromatic amine and 1-trifluoromethyl-1,2-iodobenzoyl-3(H)-ketone serve as raw materials and react under the condition that the alkali and/or nickel compound exists through the amino positioning effect on aromatic nucleus. The synthesis steps of the method are simple, the cost of the raw materials is low, the production cost of trifluoromethylamine can be greatly reduced, and large-scale industrialized production is promoted.
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Paragraph 0190-0194
(2018/09/28)
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- Synthetic method of aminobenzotrifluoride and derivant thereof
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The invention discloses a synthetic method of aminobenzotrifluoride and a derivant thereof. By adopting a method for performing amino-ortho-position trifluoromethylation on an amino-benzene compound,trifluoromethyl trimethylsilane is used a reaction reagent, free radical substitution reaction is carried out on an amino-ortho-position of the amino-benzene compound and then trifluoromethylation isdirectly carried out, so that a target product is obtained. The method disclosed by the invention has the advantages that raw materials are cheap and easy to obtain, the production is convenient, precious metal is not needed, environmental protection and safety are achieved, and purification is easy to carry out; the method can be developed into an industrial production method. Based on that, according to the synthetic method disclosed by the invention, screening and optimization on synthetic conditions of the compound are also carried out, so that the reaction yield is further improved.
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Paragraph 0050; 0051; 0104
(2018/09/13)
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- Iron(III)-Catalyzed Chlorination of Activated Arenes
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A general and regioselective method for the chlorination of activated arenes has been developed. The transformation uses iron(III) triflimide as a powerful Lewis acid for the activation of N-chlorosuccinimide and the subsequent chlorination of a wide range of anisole, aniline, acetanilide, and phenol derivatives. The reaction was utilized for the late-stage mono- and dichlorination of a range of target compounds such as the natural product nitrofungin, the antibacterial agent chloroxylenol, and the herbicide chloroxynil. The facile nature of this transformation was demonstrated with the development of one-pot, tandem, iron-catalyzed dihalogenation processes allowing highly regioselective formation of different carbon-halogen bonds. The synthetic utility of the resulting dihalogenated aryl compounds as building blocks was established with the synthesis of natural products and pharmaceutically relevant targets.
- Mostafa, Mohamed A. B.,Bowley, Rosalind M.,Racys, Daugirdas T.,Henry, Martyn C.,Sutherland, Andrew
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p. 7529 - 7537
(2017/07/26)
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- Visible-light-mediated direct perfluoroalkylation and trifluoromethylation of free anilines
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A mild, operationally simple method for direct perfluoroalkylation and trifluoromethylation of anilines through visible-light-mediated photoredox catalysis from broadly available perfluoroalkyl iodides and free anilines is described. The method provides a facile route for application in drug discovery and development.
- He, Chun-Yang,Gu, Ji-Wei,Zhang, Xingang
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supporting information
p. 3939 - 3941
(2017/09/21)
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- Nickel(II)-Catalyzed Site-Selective C-H Bond Trifluoromethylation of Arylamine in Water through a Coordinating Activation Strategy
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The first example of nickel(II)-catalyzed site-selective C-H bond trifluoromethylation of arylamine in water is established. In this transformation, a coordinating activation strategy is performed by the utilization of picolinamide as a directing group, and target products are obtained in moderate to good yields. In addition, the catalyst-in-water system can be reutilized eight times with a slight loss of catalytic activity and applied in the green, concise synthesis of acid red 266. Furthermore, a series of control experiments verify that a single-electron transfer mechanism is responsible for this reaction.
- Xu, Jun,Qiao, Li,Shen, Jiabin,Chai, Kejie,Shen, Chao,Zhang, Pengfei
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supporting information
p. 5661 - 5664
(2017/10/25)
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- Palladium-Catalyzed Trifluoromethylation of (Hetero)Arenes with CF3Br
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The CF3 group is an omnipresent motif found in many pharmaceuticals, agrochemicals, catalysts, materials, and industrial chemicals. Despite well-established trifluoromethylation methodologies, the straightforward and selective introduction of such groups into (hetero)arenes using available and less expensive sources is still a major challenge. In this regard, the selective synthesis of various trifluoromethyl-substituted (hetero)arenes by palladium-catalyzed C-H functionalization is herein reported. This novel methodology proceeds under comparably mild reaction conditions with good regio- and chemoselectivity. As examples, trifluoromethylations of biologically important molecules, such as melatonin, theophylline, caffeine, and pentoxifylline, are showcased.
- Natte, Kishore,Jagadeesh, Rajenahally V.,He, Lin,Rabeah, Jabor,Chen, Jianbin,Taeschler, Christoph,Ellinger, Stefan,Zaragoza, Florencio,Neumann, Helfried,Brückner, Angelika,Beller, Matthias
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supporting information
p. 2782 - 2786
(2016/02/27)
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- Para-Selective Halogenation of Nitrosoarenes with Copper(II) Halides
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The para-selective direct bromination and chlorination of nitrosoarenes with copper(II) bromide and chloride is reported. Under mild reaction conditions, a range of halogenated arylnitroso compounds are obtained in moderate to good yields with high regioselectivity. Additionally, the versatility of the method is demonstrated by the development of a one-pot procedure to obtain the corresponding para-halogenated aniline- and nitrobenzene derivatives.
- Van Der Werf, Angela,Selander, Nicklas
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supporting information
p. 6210 - 6213
(2016/01/09)
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- Visible-light-promoted radical C-H trifluoromethylation of free anilines
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The trifluoromethyl-substituted anilines are biologically active compounds and useful building blocks. In this communication, we have developed the first visible-light-induced radical trifluoromethylation of free anilines with the commercially available and easily handled Togni reagent at room temperature. The resulting products were successfully transformed into a variety of valuable fluorine-containing molecules and heterocyclic compounds. This protocol provides an economical and powerful route to trifluoromethylated free anilines.
- Xie, Jin,Yuan, Xiangai,Abdukader, Ablimit,Zhu, Chengjian,Ma, Jing
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supporting information
p. 1768 - 1771
(2014/04/17)
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- Copper-free direct C-H trifluoromethylation of acetanilides with sodium trifluoromethanesulfinate
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A copper-free direct C-H ortho trifluoromethylation of electron-deficient 4-substituted acetanilides using Langlois reagent (NaSO2CF3) as the CF3 source in the presence of tert-butyl hydroperoxide (tBuOOH, TBHP) was developed.
- Wu, Mingxi,Ji, Xinfei,Dai, Wenpeng,Cao, Song
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p. 8984 - 8989
(2015/01/09)
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- Regioselective chlorination and bromination of unprotected anilines under mild conditions using copper halides in ionic liquids
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By using ionic liquids as solvents, the chlorination or bromination of unprotected anilines at the para-position can be achieved in high yields with copper halides under mild conditions, without the need for potentially hazardous operations such as supplementing oxygen or gaseous HCl.
- Wang, Han,Wen, Kun,Nurahmat, Nurbiya,Shao, Yan,Zhang, He,Wei, Chao,Li, Ya,Shen, Yongjia,Sun, Zhihua
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supporting information; experimental part
p. 744 - 748
(2012/06/30)
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- Preparation of 2-amino-5-halobenzotrifluoride
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2-Amino-5-halobenzotrifluorides are prepared to the virtual exclusion of other monohalogenated isomers by halogenating an aminobenzotrifluoride with a hydrohalide acid in the presence of selected oxidants.
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- Succinimido azo dyestuffs
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The invention relates to water-insoluble azo dyestuffs of the formula SPC1 In which A represents the residue of a diazo component of the azobenzene series, R1 a hydrogen atom or an alkyl group which may be substituted which may be substituted, R2 an alkyl group which may be substituted, R3 represents a divalent organic residue which together with the grouping EQU1 may form a 5- to 7-membered heterocycle, and X represents a hydrogen atom or an alkyl, alkoxy, aryloxy or arylmercapto group. The dyestuffs dye polyester fibre in orange, red or blue shades with good fastness: the use of such succinimido containing azo dyestuffs in imparting blue to red color to fibers or fabrics of wool, cellulose triacetate, polyamides and polyesters. The dyeings display excellent fastness to light, sublimation and abrasion on polyester fibers.
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