98-56-6Relevant articles and documents
Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
Demonti, Luca,Mézailles, Nicolas,Nebra, Noel,Saffon-Merceron, Nathalie
supporting information, p. 15396 - 15405 (2021/10/12)
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.
Novel synthetic method of halogenated aromatic hydrocarbon
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Paragraph 0017-0032, (2020/01/25)
The invention discloses a novel synthetic method of halogenated aromatic hydrocarbon, wherein p-chlorotoluene is used as a raw material, copper chloride or cuprous chloride is used as a catalyst, andp-chlorobenzotrifluoride is synthesized through two steps of chlorination and fluorination. Compared with the method in the prior art, the method of the invention has the following characteristics that raw materials are subjected to heating dehydration treatment in a dehydration kettle, so that the chlorination side reactions are few, the product purity is high, the grading chlorination device does not need to be additionally arranged, the technological process is simple, and the operation is convenient; and by adding the catalyst in batches in the chlorination process, the use efficiency of the catalyst is improved, so that the emission of the byproducts and the waste gas generated by the chlorination reaction in production is greatly reduced, and the emission of pollutants in the production process is reduced.
Novel fluorination process of p-chlorobenzotrifluoride
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Paragraph 0014; 0016, (2019/12/02)
The invention discloses a novel fluorination process of p-chlorobenzotrifluoride. P-chlorotoluene is used as a raw material, and 4-chlorobenzotrifluoride is synthesized through two steps of chlorination and fluorination. Compared with the prior art, the fluorination process has the advantages of no catalyst, lower cost than other organic catalysts or noble metal catalysts, convenience in recoveryand no pollution to the environment; a solvent-free fluorination process is adopted, so that the emission of by-products and waste gas of a solvation reaction is greatly reduced, and the emission of pollutants in the production process is reduced.
Synthesis method of 4-chlorobenzotrifluoride
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Paragraph 0020-0035, (2019/12/02)
The invention discloses a synthetic method of 4-chlorobenzotrifluoride. P-chlorotoluene is used as a raw material, and 4-chlorobenzotrifluoride is synthesized through two steps of chlorination and fluorination. Compared with the prior art, the raw materials are subjected to heating dehydration treatment in the dehydration kettle, chlorination side reactions are few, the product purity is high, a graded chlorination device does not need to be added, the technological process is simple, and operation is convenient; according to the chlorination process, a mode of adding the catalyst in batches is adopted, so that the use efficiency of the catalyst is improved, the emission of byproducts and waste gas generated by chlorination reaction in production is greatly reduced, and the emission of pollutants in the production process is reduced.
Isolation of OH-bridged Ag(i)/Cu(iii) and ion-pair Cu(i)/Cu(iii) trifluoromethyl complexes with monophosphines
Xiao, Chang,Zhang, Song-Lin
supporting information, p. 848 - 853 (2019/01/21)
Cu(iii)-CF3 complexes are important intermediates of both synthetic and mechanistic interest. This study describes the isolation, and spectroscopic and X-ray crystallographic characterization of CuIII-CF3 complexes 2-4 with typical monophosphine ligands PPh3 and Buchwald-type biarylmonophosphines. Distinct from the ion-pair [P2Cu(i)]+[Cu(iii)(CF3)4]? structures of 2 and 4 (P: PPh3 or SPhos), complex 3 exhibits a novel OH-bridged Ag(i)-Cu(iii) dinuclear structure with XPhos-coordinated linear Ag(i) and square planar Cu(iii) components. This is the first heterobimetallic Cu(iii)-CF3 complex confirmed by both solution-phase NMR spectroscopy and solid state X-ray crystal structure analysis. Complex 3 is found to have the LUMO orbital of major σ*(Cu-CF3) nature and electrophilic CF3 ligands. Accordingly, complex 3 is able to trifluoromethylate 2 equivalents of aryl boronic acids in up to quantitative yields, regardless of the inert or oxidative conditions. In contrast, the ion-pair complexes 2 and 4 show low reactivity. This study enriches the coordination and reactivity chemistry of Cu(iii)-CF3 compounds and shows the feasibility of modulation of structures and reactivity by ligand design, which may inspire future efforts on Cu(iii)-CF3 chemistry.
Au@ZnO Core-Shell: Scalable Photocatalytic Trifluoromethylation Using CF3CO2Na as an Inexpensive Reagent under Visible Light Irradiation
Bazyar, Zahra,Hosseini-Sarvari, Mona
supporting information, p. 2345 - 2353 (2019/10/16)
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.
Cathodic C-H Trifluoromethylation of Arenes and Heteroarenes Enabled by an in Situ-Generated Triflyltriethylammonium Complex
Cantillo, David,Jud, Wolfgang,Kappe, C. Oliver,Maljuric, Snjezana
supporting information, (2019/10/08)
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.
Aryl Sulfonium Salts for Site-Selective Late-Stage Trifluoromethylation
Ye, Fei,Berger, Florian,Jia, Hao,Ford, Joseph,Wortman, Alan,B?rgel, Jonas,Genicot, Christophe,Ritter, Tobias
supporting information, p. 14615 - 14619 (2019/09/17)
Incorporation of the CF3 group into arenes has found increasing importance in drug discovery. Herein, we report the first photoredox-catalyzed cross-coupling of aryl thianthrenium salts with a copper-based trifluoromethyl reagent, which enables a site-selective late-stage trifluoromethylation of arenes. The reaction proceeds with broad functional group tolerance, even for complex small molecules on gram scale. The method was further extended to produce pentafluoroethylated derivatives.
Mechanism of Photoredox-Initiated C-C and C-N Bond Formation by Arylation of IPrAu(I)-CF3 and IPrAu(I)-Succinimide
Kim, Suhong,Toste, F. Dean
, p. 4308 - 4315 (2019/01/25)
Herein, we report on the photoredox-initiated gold-mediated C(sp2)-CF3 and C(sp2)-N coupling reactions. By adopting gold as a platform for probing metallaphotoredox catalysis, we demonstrate that cationic gold(III) complexes are the key intermediates of the C-C and C-N coupling reactions. The high-valent gold(III) intermediates are accessed by virtue of photoredox catalysis through a radical chain process. In addition, the bond-forming step of the coupling reactions is the reductive elimination from cationic gold(III) intermediates, which is supported by isolation and crystallographic characterization of key Au(III) intermediates.
Ligand-free trifluoromethylation of iodoarenes by use of 2-Aryl-2-trifluoromethylbenzimidazoline as new trifluoromethylating reagent
Miyagawa, Masamichi,Ishikawa, Taisuke,Shinkai, Kota,Akiyama, Takahiko
supporting information, p. 29 - 31 (2019/01/04)
N-Methyl 2-aryl-2-trifluoromethylbenzimidazolines were synthesized and utilized in the trifluoromethylation reaction of iodoarenes in the presence of copper(I) salt and base. Iodoarenes bearing electron-donating and electron-withdrawing groups were tolerant to this reaction in the absence of a ligand and gave trifluorotoluene derivatives in good to high yields.
