- One-pot synthesis of 2-trifluoromethyl and 2-difluoromethyl substituted benzo-1,3-diazoles
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2-Trifluoromethyl and 2-difluoromethyl substituted benzimidazole, benzoxazole and benzothiazole derivatives were efficiently prepared through a one-pot reaction of trifluoroacetic acid and difluoroacetic acid, respectively, with commercially available o-p
- Ge, Fenglian,Wang, Zengxue,Wan, Wen,Lu, Wencong,Hao, Jian
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- Recyclable copper-catalyzed cyclization of o-haloanilides and metal sulfides: An efficient and practical access to substituted benzothiazoles
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An efficient heterogeneous copper-catalyzed cyclization of o-haloanilides and metal sulfides has been achieved via the C–S coupling in DMF at 80 or 140 °C in the existence of an MCM-41-bound NHC-Cu(I) catalyst and then intramolecular condensation, delivering a wide range of substituted benzothiazoles in mostly good to high yields. This new MCM-41-NHC-CuI complex can facilely be obtained by a two-step procedure starting from easily accessible and inexpensive reagents and reused more than seven times without any significant loss of its catalytic efficiency. The present protocol has been successfully applied to the gram-scale synthesis of two antitumor agents 5F203 and PMX 610.
- Cai, Mingzhong,Hao, Wenyan,Huang, Wencheng,Ye, Qian
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- Metallaphotoredox Perfluoroalkylation of Organobromides
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Ruppert-Prakash type reagents (TMSCF3, TMSC2F5, and TMSC3F7) are readily available, air-stable, and easy-to-handle fluoroalkyl sources. Herein, we describe a mild, copper-catalyzed cross-coupling of these fluoroalkyl nucleophiles with aryl and alkyl bromides to produce a diverse array of trifluoromethyl, pentafluoroethyl, and heptafluoropropyl adducts. This light-mediated transformation proceeds via a silyl-radical-mediated halogen atom abstraction pathway, which enables perfluoroalkylation of a broad range of organobromides of variable steric and electronic demand. The utility of the method is demonstrated through the late-stage functionalization of several drug analogues.
- Zhao, Xiangbo,MacMillan, David W. C.
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supporting information
p. 19480 - 19486
(2020/12/18)
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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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- A radical approach to the copper oxidative addition problem: Trifluoromethylation of bromoarenes
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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.
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p. 1010 - 1014
(2018/06/12)
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- RODENTIA ANIMAL REPELLENT
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PROBLEM TO BE SOLVED: To provide a repellent having a superior repellent activity for Rodentia animals, and a repellent method for Rodentia animals. SOLUTION: A Rodentia animal repellent contains, as an active ingredient, a compound represented by the for
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Paragraph 0032
(2016/10/27)
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- Metal-free synthesis of benzothiazoles from disulfides of 2-aminobenzenethiol and carboxylic acid via PCl3-promoted tandem reaction
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A metal-free process for the synthesis of benzothiazoles via PCl3-promoted cleavage/acylation/ cyclization of disulfides and carboxylic acids has been developed. In addition to acting as the acylating reagent which converted carboxylic acids into acyl chlorides, PCl3 also converted disulfides to thiols, which promoted disulfides of 2-aminobenzenethiol reacted with carboxylic acid to produce benzothiazoles. The developed method is applicable to a wide range of carboxylic acids containing different functional groups.
- Du, Guangyan,Zhu, Ning,Han, Limin,Hong, Hailong,Suo, Quanling
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p. 1723 - 1734
(2015/12/12)
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- FeCl3/ultrasound mediated reaction of 2-aminothiophenol with aldehydes in water: Synthesis of 2-substituted benzothiazoles of pharmacological interest
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We report a FeCl3?6H2O mediated green and rapid access to benzothiazole derivatives having a substituent at C-2 via the condensation of 2-aminothiophenol with various aldehydes under ultrasound irradiation and air. The reaction progressed well in water affording the expected products in good yields. Two of these compounds known to be potent anticancer agents showed good interactions with PDE4B in silico and inhibited this enzyme when tested in vitro.
- Srinivas, Ponasanapalli Tirumala Venkata Ankayya,Bhavani, Sallagundla,Rambabu, Dandela,Rao, Mandava Venkata Basaveswara,Kapavarapu, Ravikumar,Pal, Manojit
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p. 457 - 465
(2015/06/22)
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- RODENTIA ANIMAL REPELLENT
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Provided are a repellent having a superior repellent activity for Rodentia animal and a repellent method for Rodentia animal. A Rodentia animal repellent containing, as an active ingredient, a compound represented by the formula (1) wherein Z1
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Paragraph 0032
(2016/06/06)
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- One-pot sandmeyer trifluoromethylation and trifluoromethylthiolation
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Practical one-pot procedures were developed for both Sandmeyer-type trifluoromethylations and trifluoromethylthiolations. Starting from broadly available (hetero)aromatic amines, various benzotrifluorides were synthesized in high yields via in situ diazotization and copper-mediated trifluoromethylation using the inexpensive Ruppert-Prakash trifluoromethylating reagent. In the presence of sodium thiocyanate as a sulfur source, aryl trifluoromethyl thioethers are exclusively formed.
- Bayarmagnai, Bilguun,Matheis, Christian,Risto, Eugen,Goossen, Lukas J.
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supporting information
p. 2343 - 2348
(2014/07/21)
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- Efficient syntheses of 2-fluoroalkylbenzimidazoles and -benzothiazoles
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We report an efficient one-step route to 2-fluoroalkylbenzimidazoles and -benzothiazoles via the condensation of fluorinated carboxylic acids and aromatic diamines or aminothiophenols. Additionally, we describe the syntheses of fluoroalkyl-azabenzimidazoles, -purines, and -imidazolopyrazines. This method is high-yielding with broad scope and is operationally simple with potential application to parallel synthesis.
- René, Olivier,Souverneva, Alexandra,Magnuson, Steven R.,Fauber, Benjamin P.
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supporting information
p. 201 - 204
(2013/02/22)
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- Copper-catalyzed direct C-H oxidative trifluoromethylation of heteroarenes
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This article describes the copper-catalyzed oxidative trifluoromethylation of heteroarenes and highly electron-deficient arenes with CF 3SiMe3 through direct C-H activation. In the presence of catalyst Cu(OAc)2, ligand 1,10-phenanthroline and cobases tert-BuONa/NaOAc, oxidative trifluoromethylation of 1,3,4-oxadiazoles with CF3SiMe3 proceeded smoothly using either air or di-tert-butyl peroxide as an oxidant to give the corresponding trifluoromethylated 1,3,4-oxadiazoles in high yields. Di-tert-butyl peroxide was chosen as the suitable oxidant for oxidative trifluoromethylation of 1,3-azoles and perfluoroarenes. Cu(OH)2 and Ag2CO3 were the best catalyst and oxidant for direct oxidative trifluoromethyaltion of indoles. The optimum reaction conditions enable oxidative trifluoromethylation of a range of heteroarenes that bear numerous functional groups. The prepared trifluoromethylated heteroarenes are of importance in the areas of pharmaceuticals and agrochemicals. The preliminary mechanistic studies of these oxidative trifluoromethylations are also reported.
- Chu, Lingling,Qing, Feng-Ling
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supporting information; experimental part
p. 1298 - 1304
(2012/02/16)
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- Switching reaction pathways of trifluoromethylated thiobenzanilides by choice of different oxidative systems
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Trifluoromethylated thiobenzanilides are efficiently converted to 2-trifluoromethylbenzothiazoles via intramolecular oxidative cyclization under CAN/NaHCO3 oxidation, while the dimerized products with "-S-S-" bond linkage are obtained when PIDA
- Zhu, Jiangtao,Xie, Haibo,Li, Shan,Chen, Zixian,Wu, Yongming
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p. 306 - 309
(2011/06/20)
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- Copper-catalyzed thiolation annulations of 1,4-dihalides with sulfides leading to 2-trifluoromethyl benzothiophenes and benzothiazoles
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Copper-catalyzed double thiolation reaction of 1,4-dihalides with sulfides has been developed for selectively synthesizing 2-trifluoromethyl benzothiophenes and benzothiazoles. In the presence of CuI, a variety of 2-halo-1-(2-haloaryl)-3,3,3-trifluoropropylenes smoothly underwent the thiolation annulation with Na2S to afford 2-trifluoromethyl benzothiophenes in moderate to good yields. Moreover, the conditions are compatible with N-(2-haloaryl)trifluoroacetimidoyl chlorides in the presence of NaHS and K3PO4, leading to 2-trifluoromethyl benzothiazoles.
- Li, Chun-Lin,Zhang, Xing-Guo,Tang, Ri-Yuan,Zhong, Ping,Li, Jin-Heng
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experimental part
p. 7037 - 7040
(2010/11/17)
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- A general and straightforward method for the synthesis of 2-trifluoromethylbenzothiazoles
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An efficient one-pot method for the synthesis of 2- trifluoromethylbenzothiazoles by the treatment of trifluoromethylimidoyl chlorides with sodium hydrosulfide hydrate using PdCl2 as the sole catalyst in DMSO is described. The reaction proceeds via thiolation/C-H bond functionalization/C-S bond formation in moderate to high yields with good functional group tolerance.
- Zhu, Jiangtao,Chen, Zixian,Xie, Haibo,Li, Shan,Wu, Yongming
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supporting information; experimental part
p. 2434 - 2436
(2010/07/10)
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- A novel synthesis of 2-per(poly)fluoroalkyl-1H-benzimidazoles or 2-per(poly) fluoroalkyl benzothiazoles
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A new method for the preparation of 2-per(poly)fluoroalkyl-1H-benzimidazoles or 2-per(poly)fluoroalkyl benzothiazoles from reaction of readily available α-per(poly)fluoroalkyl aldehydes with o-phenylenediamine or 2-aminobenzenethiol is presented. A possible reaction pathway is suggested.
- Wang, Quan-Fu,Mao, Yun-Yu,Zhu, Shi-Zheng,Hu, Chang-Ming
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p. 141 - 143
(2007/10/03)
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- Synthesis and reactivity of 3-chloro-3-trifluoromethylacroleins: stabilisation of the tetrahedral intermediate in a nucleophilic vinylic "substitution"
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Trifluoromethyl ketones 1a-d reacted with the Vilsmeier reagent to give CF3-substituted β-chloro-vinylaldehydes 2a-d in good yields.Using 2-amino-ethanethiol as a nucleophile, a different regiochemistry of cyclization that depends on a methyl or trifluoromethyl substituent was observed.The cyclization of trifluoromethyl compounds 2a and 2e into thiazolidines 7 or 24 results in the stabilization of the tetrahedral intermediate by the captodative effect.We report the first direct substitution of a tetrahedral intermediate (instead of elimination) in a nucleophilic vinylic reaction. trifluoromethylacroleins / Michael addition / tetrahedral intermediate
- Alvernhe, Gerard,Greif, Dieter,Langlois, Bernard,Laurent, Andre,Drean, Isabelle Le,et al.
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p. 167 - 172
(2007/10/02)
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- Trifluoromethyl Substitution Affects the Regiochemistry of Cyclising Condensation in 1,4 Substitution Processes
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β-Trifluoromethyl β-chloroacrolein 2 reacts with 2-mercaptoethylamine 3 to produce thiazolidine 5 instead of the expected thiazepine 8.The reason of this behaviour is the formation of the tetrahedral intermediate 6 because of stabilisation by the trifluoromethyl group; an intramolecular substitution takes place faster than a 1,4 addition-elimination process. Key Words: Trifluoromethyl; Michael reaction; regiochemistry; thiazolidine; thiazepine
- Alvernhe, Gerard M.,Laurent, Andre J.,Drean, Isabelle M. Le,Selmi, Abdelaziz
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p. 2483 - 2486
(2007/10/02)
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- Synthesis of β-chloro(trifluoromethyl)acroleins and a specific reaction towards β-aminothiols
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β-chloro-β-(trifluoromethyl)acroleins and β-chloro-α-(trifluoromethyl)-acrolein have been synthesized through Vilsmeier's reaction. A specific 1,4-addition of the nitrogen atom from β-aminothiols is observed.
- Alvernhe, Gerard,Langlois, Bernard,Laurent, Andre,Le Drean, Isabelle,Selmi, Abdelaziz,Weissenfels, Menfred
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p. 643 - 646
(2007/10/02)
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- Reaction Products of 2-Aminobenzenethiol with some β-Diketones
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2-Aminobenzenethiol undergoes condensation reactions with several β-diketones (CH3, CF3 and C6H5 substituents) to form benzothiazolines.Conversion to benzothiazines and benzothiazoles occurs in some instances, as documented by isolation and spectroscopic characterization of the products.
- Alyea, Elmer C.,Malek, Abdul
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p. 1325 - 1327
(2007/10/02)
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