- Direct Superacid-Promoted Difluoroethylation of Aromatics
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Under superacid conditions, aromatic amines are directly and regioselectively 1,1-difluoroethylated. Low temperature in situ NMR studies confirmed the presence of benzylic α-fluoronium and α-chloronium ions as key intermediates in the reaction. This method has a wide substrate scope and can be applied to the late-stage functionalization of natural alkaloids and active pharmaceutical ingredients.
- Artault, Maxime,Vitse, Kassandra,Martin-Mingot, Agnès,Thibaudeau, Sébastien
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supporting information
(2021/12/22)
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- Complementary Site-Selective Halogenation of Nitrogen-Containing (Hetero)Aromatics with Superacids
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Site-selective functionalization of arenes that is complementary to classical aromatic substitution reactions remains a long-standing quest in organic synthesis. Exploiting the generation of halenium ion through oxidative process and the protonation of the nitrogen containing function in HF/SbF5, the chlorination and iodination of classically inert Csp2?H bonds of aromatic amines occurs. Furthermore, the superacid-promoted (poly)protonation of the molecules acts as a protection, favoring the late-stage selective halogenation of natural alkaloids and active pharmaceutical ingredients.
- Mamontov, Alexander,Martin-Mingot, Agnès,Métayer, Benoit,Karam, Omar,Zunino, Fabien,Bouazza, Fodil,Thibaudeau, Sébastien
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supporting information
p. 10411 - 10416
(2020/07/30)
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- Method for preparing CLT acid by taking m-toluidine as raw material
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The invention discloses a method for preparing CLT acid by taking m-toluidine as a raw material, and belongs to the field of chemical synthesis. The method solves the problems that existing CLT acid production is low in yield, not environmentally friendly and the like. The method comprises: S01) an acylation step, namely a step of reacting m-toluidine and acetic anhydride to obtain acylation reaction solution; S02) a chlorination step, namely a step of adding acetic acid and concentrated hydrochloric acid into the acylation reaction solution, then adding hydrogen peroxide, and finally adding an aqueous solution containing sodium sulfite to obtain a chlorination reaction solution; S03) a hydrolyzing step to form salt, namely a step of adding concentrated sulfuric acid into the chlorinationreaction solution, and removing the solvent after reaction; S04) a transposition sulfonation step, namely a step of adding chlorobenzene into the solvent-removed reaction solution obtained in the stepS03, heating the mixture, adding dichlorobenzene, heating the mixture again, reacting the mixture for 7-10 hours with the temperature of the system being maintained at a temperature higher than 170 DEG C, and stopping heating; and S05) a step of post-treatment to obtain a finished product that is the CLT acid. The method has the advantages of environmental protection and the like.
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Paragraph 0053; 0056-0057
(2019/12/02)
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- Sulfonium Salts as Alkylating Agents for Palladium-Catalyzed Direct Ortho Alkylation of Anilides and Aromatic Ureas
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A novel method for the ortho alkylation of acetanilide and aromatic urea derivatives via C-H activation was developed. Alkyl dibenzothiophenium salts are considered to be new reagents for the palladium-catalyzed C-H activation reaction, which enables the transfer of methyl and other alkyl groups from the sulfonium salt to the aniline derivatives under mild catalytic conditions.
- Simkó, Dániel Cs.,Elekes, Péter,Pázmándi, Vivien,Novák, Zoltán
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supporting information
p. 676 - 679
(2018/02/09)
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- Mild and efficient palladium-catalyzed direct trifluoroethylation of aromatic systems by C-H activation
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The introduction of trifluoroalkyl groups into aromatic molecules is an important transformation in the field of organic and medicinal chemistry. However, the direct installation of fluoroalkyl groups onto aromatic molecules still represents a challenging and highly demanding synthetic task. Herein, a simple trifluoroethylation process that relies on the palladium-catalyzed C-H activation of aromatic compounds is described. With the utilization of a highly active trifluoroethyl(mesityl)iodonium salt, the developed catalytic method enables the first highly efficient and selective trifluoroethylation of aromatic compounds. The robust catalytic procedure provides the desired products in up to 95 % yield at 25 °C in 1.5 to 3 hours and tolerates a broad range of functional groups. The utilization of hypervalent reagents opens new synthetic possibilities for direct alkylations and fluoroalkylations in the field of transition-metal-catalyzed C-H activation.
- T?th, Balázs L.,Kovács, Szabolcs,Sályi, Gerg?,Novák, Zoltán
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supporting information
p. 1988 - 1992
(2016/02/18)
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- Imidazolium Salt Catalyzed para -Selective Halogenation of Electron-Rich Arenes
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A highly para-selective halogenation of arenes bearing coordinating groups in the presence of a dimidazolium salt as a catalyst is reported. A series of electron-rich p-haloarenes were prepared in good yields and good to excellent selectivities. We also propose a plausible mechanism for the catalytic reaction.
- Chen, Jie,Xiong, Xiaoyu,Chen, Zenghua,Huang, Jianhui
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supporting information
p. 2831 - 2834
(2015/12/18)
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