- 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)
-
- A metal-free picolinamide assisted electrochemical ortho-trifluoromethylation of arylamines
-
An eco-friendly and effective electrochemical process was developed for the ortho-trifluoromethylation of arylamines using CF3SO2Na as the trifluoromethyl source, affording the desired products in moderate to good yields with high regioselectivity under mild reaction conditions. Importantly, the requirement for both transition metals and oxidants utilized in previous methods were avoided. A radical mechanism was proposed on the basis of various control experiments.
- Wang, Kai,Hou, Jiahao,Wei, Tingting,Zhang, Changjun,Bai, Renren,Xie, Yuanyuan
-
-
- o-aminotrifluorotoluene synthesis method
-
The invention discloses an o-aminotrifluorotoluene synthesis method, wherein trifluorotoluene is used as a raw material, and a target compound is obtained through two-step reaction of nitration and reduction. Compared with the method in the prior art, the method of the invention has the following characteristics that trifluorotoluene is used as the raw material, so that the source is wide, and thepreparation is convenient; the nitration reaction is carried out at a normal pressure and a low temperature, so that the corrosion of the material to the pipeline and the equipment is small, and thenitration reaction is safe and reliable to the environment and operators; and the cheap nickel catalyst is used for replacing the common noble metal catalysts such as palladium, platinum and the like,so that the production cost is reduced, the methanol as the solvent is convenient to recover and can be recycled, and the emission of organic matters in the production process is reduced.
- -
-
Paragraph 0006; 0013-0021
(2020/01/25)
-
- Transition metal-free direct C–H trifluoromethyltion of (hetero)arenes with Togni's reagent
-
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
-
supporting information
(2019/12/30)
-
- Visible-light-induced Pd-catalyzed: Ortho -trifluoromethylation of acetanilides with CF3SO2Na under ambient conditions in the absence of an external photocatalyst
-
A visible-light-induced Pd-catalyzed ortho-trifluoromethylation of acetanilides with CF3SO2Na was developed. The reaction proceeded smoothly at room temperature in air without any external photocatalyst or additive, providing the desired products in moderate to good yields with good functional group tolerance and regioselectivity.
- Zou, Long,Li, Pinhua,Wang, Bin,Wang, Lei
-
p. 3737 - 3740
(2019/04/01)
-
- Eco-friendly hydrogenation of aryl azides to primary amines on graphene oxide-decorated bimetallic Rh-Pt nanoparticles (RhPt@GO NPs)
-
Graphene oxide-supported rhodium/platinum (Rh-Pt) nanoparticles (Rh-Pt@GO NPs) are a promising catalyst for the reduction of aryl azides to primary amines. Rh-Pt@GO NPs have been produced by the microwave-assisted sonochemical method. This catalyst showed superior catalytic activity to afford quantitative yields of primary amines under an extremely mild condition in the presence of sodium borohydride. The synthesized novel catalyst was easily recovered by centrifugation and reused without loss of its catalytic activity. The spectroscopic analyses of the RhPt@GO NPs indicated the formation of highly crystalline, monodisperse, and colloidally stable RhPt@GO NPs.
- Kilbas, Benan,Kara, Belguzar Yasemin
-
-
- Synthetic method of aminobenzotrifluoride and derivant thereof
-
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.
- -
-
Page/Page column 7-11
(2018/09/13)
-
- Aminobenzotrifluoride solvent-free hydrogenation reduction process
-
The invention relates to an aminobenzotrifluoride solvent-free hydrogenation reduction process and belongs to the field of pesticide chemical product preparation methods. The process mainly comprisesthe following steps: putting a raw material, namely nitryl benzotrifluoride, into a reaction kettle, performing a hydrogenation reduction reaction under conditions that no solvent is used and raney nickel is adopted as a catalyst, after the reaction is completed, cooling, filtering at normal pressure, recycling the catalyst, and performing negative pressure distillation on filtrate, thereby obtaining aminobenzotrifluoride. The whole process is carried out under a solvent-free process condition, so that emission of organic matters in the conventional production process is reduced; the consequence that a carbaryl byproduct is generated from reactions of solvents such as methanol with reduced amino is avoided, so that the product purity can be improved; compared with a conventional solvent method, the process is relatively low in temperature, relatively low in energy consumption, low in production cost and beneficial to energy conservation and emission reduction.
- -
-
Paragraph 0024; 0026; 0027; 0028; 0030; 0032
(2018/10/02)
-
- O-aminotrifluorotoluene solvent-free hydrogenation reduction technology
-
The invention relates to an o-aminotrifluorotoluene solvent-free hydrogenation reduction technology belonging to the field of preparation methods of pesticide chemical products. The technology mainlycomprises the following steps: adding raw material nitryl trifluorotoluene into a reduction reaction kettle, carrying out hydrogenation reduction reaction under the conditions that no solvent is usedand raney nickel is taken as a catalyst, after the reaction is finished, cooling, filtering at normal pressure and recycling the catalyst, and carrying out negative pressure rectification on filtrate,so that o-aminotrifluorotoluene can be obtained. The whole process adopts the solvent-free technological condition, and discharge of organic matters in the traditional production process is reduced;the defect that solvents such as methanol react with reduced amino and carbaryl byproducts are generated is overcome, and product purity is improved; and compared with an existing solvent method, temperature is relatively low, energy consumption is relatively low, production cost is reduced, and energy conservation and discharge reduction are facilitated.
- -
-
Paragraph 0011; 0020-0025
(2018/09/11)
-
- Nickel-Catalyzed Direct C-H Trifluoromethylation of Free Anilines with Togni's Reagent
-
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
-
supporting information
p. 3732 - 3735
(2018/07/22)
-
- Preparation method of trifluoromethylamine
-
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.
- -
-
Paragraph 0023-0026; 0027-0045; 0046-0056
(2018/09/28)
-
- Iron-catalyzed: Ortho trifluoromethylation of anilines via picolinamide assisted photoinduced C-H functionalization
-
A convenient, oxidant-free protocol was developed for the ortho trifluoromethylation of aniline via picolinamide assisted Fe-promoted C-H functionalization under ultraviolet irradiation. In this transformation acetone essentially acted as both a solvent to dissolve reactants and a low-cost radical initiator to efficiently generate a CF3 radical from Langlois' reagent. A broad substrate scope was tolerated and picolinamide bearing strong electron withdrawing groups also could be transformed into the corresponding products with acceptable yields. Furthermore, the value of this method has been highlighted via the efficient synthesis of the nonsteroidal anti-inflammatory drug floctafenine.
- Xia, Chengcai,Wang, Kai,Wang, Guodong,Duan, Guiyun
-
p. 2214 - 2218
(2018/04/05)
-
- Coordinating Activation Strategy-Induced Selective C?H Trifluoromethylation of Anilines
-
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
-
p. 965 - 970
(2018/02/12)
-
- A practical and highly efficient transfer hydrogenation of aryl azides using a [Ru(p-cymene)Cl2]2 catalyst and sodium borohydride
-
Various aniline derivatives were synthesized by selective reduction of aryl azides in the presence of a dichloro(p-cymene)ruthenium(II) dimer ([Ru(p-cymene)Cl2]2) via hydrolysis of sodium borohydride. The hydrogenation reactions were carried out in aqueous media at room temperature. Most of the reactions were completed within 10 min with quantitative yields.
- Kilbas, Benan,Yilmaz, Yunus Emre,Ergen, Sinem
-
p. 880 - 883
(2018/08/21)
-
- Powerful, Thermally Stable, One-Pot-Preparable, and Recyclable Electrophilic Trifluoromethylating Agents: 2,8-Difluoro- and 2,3,7,8-Tetrafluoro-S-(trifluoromethyl)dibenzothiophenium Salts
-
Although many electrophilic trifluoromethylating agents have been reported to date, practically useful reagents have yet to be developed. S-(Trifluoromethyl)dibenzothiophenium salts, known as Umemoto's reagents, have two significant drawbacks that have ha
- Umemoto, Teruo,Zhang, Bin,Zhu, Tianhao,Zhou, Xiaocong,Zhang, Peng,Hu, Song,Li, Yuanqiang
-
p. 7708 - 7719
(2017/08/14)
-
- Visible-light-mediated direct perfluoroalkylation and trifluoromethylation of free anilines
-
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
-
supporting information
p. 3939 - 3941
(2017/09/21)
-
- HALOGENATED S-(PERFLUOROALKYL) DIBENZOTHIOPHENIUM SALT AND ITS PRODUCTION METHODS
-
Halogenated S-(perfluoroalkyl) dibenzothiophenium salt represented by the following general formula (I). This compound is a new, reactive, and industrially useful reagent for perfluoroalkylating organic compounds. The reagent can be prepared by a one-pot process or a two-step reaction process from a halogenated biphenyl and easily isolated by a filtration method. In addition, the halogenated biphenyl can be recovered by desulfurization from a halogenated dibenzothiophene obtained as a side-product by the usage of the reagent.
- -
-
Page/Page column 28
(2016/07/27)
-
- Selectivity and activity in catalytic hydrogenation of azido groups over Pd nanoparticles on aluminum oxy-hydroxide
-
Azidoarenes involving various functional groups were successfully reduced to aniline derivatives using commercially available aluminium oxy-hydroxide-supported palladium (Pd/AlO(OH)) nanoparticles (0.5 wt% Pd) in an aqueous medium with sodium borohydride as the hydrogen source. To develop the green process, water was utilized in conjunction with methanol. The results demonstrated that the halogen substituted azidoarenes were selectively converted to the corresponding aniline compounds without dehalogenation. In general, all of the reactions were completed within 10-30 min at room temperature with yields of over 99%. In order to optimize the reaction conditions, the parametric effects of the solvent type and the amount of the catalyst/NaBH4 were examined. Consequently, for the first time, a novel, practical and environmentally friendly process was developed for the conversion of azidoarenes to aniline derivatives in the fluence of Pd/AlO(OH) nanoparticles.
- Kara, Belgüzar Yasemin,Kilba?, Benan,G?ksu, Haydar
-
p. 9550 - 9555
(2016/11/11)
-
- The 2,4-dimethyl-7-pentafluorosulfanyl-5-(trifluoromethyl)dibenzo[b,d] thiophenium trifluoromethanesulfonate: The SF5-analog of Umemoto salt
-
The SF5-analog of the Umemoto salt was synthesized in just two steps by combining our recently reported SF5-biaryl synthesis, via Suzuki coupling with 4-(pentafluorosulfanyl)benzenediazonium tetrafluoroborate, with Magnier's one-pot synthesis of dibenzothiophenium salts employing CF 3SO2Na and triflic anhydride. The trifluoromethylating power of this novel onium salt toward reactive arenes was tested in a survey study on small scale.
- Okazaki, Takao,Laali, Kenneth K.,Reddy, A. Srinivas
-
-
- Ionic liquids as new media for electrophilic trifluoromethylation reactions
-
The electrophilic trifluoromethylation of aniline with a range of trifluoromethyl sulfonium salts has been studied in ionic liquids as solvent. The best ionic liquid for this reaction was identified after extensive scrutiny of the influence of the cation's nature (imidazolium or pyridinium salts), the effect of the alkyl side chain length of the cation, as well as that of the counter anion. Recycling experiments have demonstrated that the purification protocol was greatly simplified over conventional reactions performed in DMF and that the solvent could be reused five times without significant loss of activity.
- Pégot, Bruce,Macé, Yohan,Urban, Céline,Diter, Patrick,Blazejewski, Jean-Claude,Magnier, Emmanuel
-
experimental part
p. 156 - 159
(2012/02/15)
-
- Facile dehalogenation of halogenated anilines and their derivatives using Al-Ni alloy in alkaline aqueous solution
-
This article describes the simple hydrodehalogenation of halogenated anilines and their derivatives by the action of Raney aluminium-nickel alloy in aqueous alkaline solution at room temperature. The reaction course was monitored by means of 1H nuclear magnetic resonance (NMR) spectroscopy and GC-MS spectra. The effect of Al and Ni and the nature and quantity of the base for effective hydrodehalogenation were studied. The possibility of lowering Al content more than 500 times and Ni content more than 10 times in the filtered mother liquor by a dehalogenation procedure was tested using precipitation. The reduction method described was satisfactorily proved for dehalogenation of polyhalogenated anilines in the multiphase dimethoxymethane/aqueous NaOH/Al-Ni reaction mixture. Dehalogenation under multi-phase conditions was demonstrated for the preparation of ortho-alkylated anilines from simply available 2-substituted-4-chloroanilines. Versita Sp. z o.o.
- Weidlich, Tomas,Prokes, Lubomir
-
experimental part
p. 590 - 597
(2012/04/10)
-
- A novel catalytic process for trifluoromethylation of bromoaromatic compounds
-
The palladium-catalyzed trifluoromethylation of aryl bromides has been achieved in micellar media. The micellar conditions result in enhanced yields and are applicable to bromoaromatics with ketone, aldehyde, hydroxyl and amine functionalities.
- Samant, Bhupesh S.,Kabalka, George W.
-
supporting information; experimental part
p. 7236 - 7238
(2011/08/22)
-
- Trifluoromethylation of various aromatic compounds by CF3I in the presence of Fe(II) compound, H2O2 and dimethylsulfoxide
-
Trifluoromethylation of aromatic and hetero-aromatic compounds by CF3I in the presence of Fe(II) compound, H2O2 and dimethylsulfoxide was investigated. Various trifluoromethylated benzene derivatives, six-membered nitrogen-containing aromatic compounds and five-membered hetero-aromatic compounds were obtained under mild conditions. General orientation of electrophilic substitution of aromatic compounds was observed similarly as reported in other radical trifluoromethylation previously.
- Kino, Tatsuhito,Nagase, Yu,Ohtsuka, Yuhki,Yamamoto, Kyoko,Uraguchi, Daisuke,Tokuhisa, Kenji,Yamakawa, Tetsu
-
experimental part
p. 98 - 105
(2010/03/03)
-
- Benchmark and Solvent-Free preparation of sulfonium salt based electrophilic trifluoromethylating reagents
-
Here we describe work devoted to the one-pot preparation of electrophilic trifluoromethylating reagents. The first part describes a reappraisal of our earlier experimental conditions and leads to an improved protocol that avoids the use of solvent: and allows better yields. The second part carefully studies the behavior of biaryl substrates, whose structures can drive the reaction through the formation of original noncyclic or tricyclic dibenzothiophenium salts. New compounds were tested, in a standard reaction with aniline, for their trifluoromethylating power and revealed equivalent or improved reactivity relative to that of existing reagents. Furthermore, contrary to common knowledge, the presence of electron-donating methyl groups gave reagents with very high activity. Wiley-VCH Verlag GmbH & Co, KGaA.
- Mace, Yohan,Raymondeau, Benoit,Pradet, Charlotte,Blazejewski, Jean-Claude,Magnier, Emmanuel
-
experimental part
p. 1390 - 1397
(2009/08/07)
-
- REACTION REAGENT FOR TRIFLUOROMETHYLATION
-
Provided is a reaction reagent for trifluoromethylation with high general versatility and good efficiency. The reaction reagent for trifluoromethylation contains an iron compound, trifluoromethyl iodide, a sulfoxide and a peroxide, and may further contain an acid. The iron compound is, for example, iron(II) sulfate, ammonium iron(II) sulfate, iron(II) tetrafluoroborate, ferrocene, bis(η5-pentamethylcyclopentadienyl)iron or an iron powder; the sulfoxide is, for example, dimethyl sulfoxide; the peroxide is, for example, hydrogen peroxide or hydrogen peroxide-urea composite; and the acid is, for example, sulfuric acid, tetrafluoroboric acid or trifluoromethanesulfonic acid.
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-
Page/Page column 8-9
(2009/08/14)
-
- Preparation and characterization of diazenyl quinolin-8-ol with trifluoromethyl substituents
-
The synthesis and properties of new monoazo dyes derived from the diazonium salts of 2-trifluoromethyl phenylamine and 4-chloro-3-trifluoromethyl phenylamine are considered.
- Yazdanbakhsh, Mohammad R.,Mahmoodi, Nosrat O.,Dabiry, Shahram
-
p. 192 - 194
(2007/10/03)
-
- New Electrophilic Trifluoromethylating Agents
-
Synthetic routes to S-(trifluoromethyl)phenyl-4-fluorophenylsulfonium triflate (8), S-(trifluoromethyl)phenyl-2,4-difluorophenylsulfonium triflate (9), S-(trifluoromethyl)phenyl-3-nitrophenylsulfonium triflate (10), and S-(trifluoromethyl)-4-fluorophenyl-3-nitrophenylsulfonium triflate (11) are described. They are stable molecules and conveniently prepared by treating phenyl trifluoromethyl sulfoxide with benzene and its derivatives. These novel electrophilic trifluoromethylating agents react under mild conditions with a variety of aromatic rings (p-hydroquinone, pyrrole, and aniline) to give trifluoromethylated compounds (2-trifluoromethyl-p-hydroquinone, 2-trifluoromethylpyrrole, 2-trifluoromethylaniline, and 4-trifluoromethylaniline) in moderate to high yields. The electrophilic trifluoromethylating potential can be altered by placing electron-withdrawing substituents on the benzene rings.
- Yang, Jing-Jing,Kirchmeier, Robert L.,Shreeve, Jean'ne M.
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p. 2656 - 2660
(2007/10/03)
-
- Synthesis of functionalized carbamates through a palladium-catalyzed reductive carbonylation of substituted nitrobenzenes
-
The palladium-catalyzed reductive carbonylation of ortho and para-substituted nitrobenzenes has proven to be an attractive route for the synthesis of functionalized carbamates. For the Pd(1,10-phenanthroline)2(triilate}2 catalyst system, the scope of the reaction has been studied. Substrates with electron-donating substituents at the para position were found to decrease the catalytic activity, most probably as a result of their relatively low oxidizing capacity. The selectivity towards the desired carbamate, however, was increased for these substrates. Under the influence of electron-withdrawing substituents the azoxybenzene and azobenzene derivatives became important side products. Introduction of large steric hindrance at the ortho position of the nitro substrates gave rise to an interesting side reaction, viz. methoxylation of the aromatic ring. The methoxylation reaction appeared to occur on an intermediate species in the catalytic cycle. Several functionalities have shown to be resistant to the reaction conditions required for the conversion of the nitro group. Especially with 4-nitrobenzoic acid, an extremely high activity and selectivity was found, thus yielding a very convenient synthesis for N-protected amines containing carboxylic acid functions. VCH Verlagsgesellschaft mbH.
- Wchman, Petra,Borst, Leo,Kamer, Paul C. J.,Van Leeuwen, Piet W. N. M.
-
-
- Kinetic study of trifluoromethylation with S-(trifluoromethyl) dibenzothiophenium salts
-
The kinetic parameters were determined for C-trifluoromethylation of aniline with S-(trifluoromethyl)dibenzothiophenium triflate (1), its 3,7-dinitro derivative (2) and S-(trifluoromethyl)diphenylsulfonium triflate (3) in DMF-d7. The higher reactivity of heterocyclic 1 compared with non-heterocyclic 3 could be explained on the basis of its greatly enhanced activation entropy (ΔS≠: -11.2 cal mol-1 K-1 for 1; -47.1 for 3), but not its enhanced activation enthalpy (ΔH≠: 21.2 kcal mol-1 for 1; 12.1 for 3). The aromatic delocalization of the heterocyclic ring may thus be only slightly disturbed by the S-trifluoromethyl substituent. The high reactivity of 2 was attributed to the great electron deficiency caused by two nitro groups in addition to the heterocyclic salt system (ΔH≠ 17.0 kcal mol-1, ΔS≠ -9.1 cal mol-1 K-1 for 2). The reaction mechanism is discussed; the conventional SN2 attack mechanism was ruled out and a mechanism for a side-on attack to the CF3-S bond may possibly be applicable.
- Ono, Taizo,Umemoto, Teruo
-
p. 163 - 166
(2007/10/03)
-
- The Bamberger reaction in hydrogen fluoride: the use of mild reductive metals for the preparation of fluoroaromatic amines
-
The reduction of nitroaromatic compounds by various metals (tin, lead, bismuth) in liquid hydrogen fluoride under an inert atmosphere leads to fluoroaromatic amines, in accord with the Bamberger reaction.Generally, a co-solvent such as pentane or methylene chloride is used.Some non-fluorinated arylamines are also formed by a competitive direct reduction of the N-arylhydroxylamine intermediate.Of the mild reductive metals studied, bismuth was the most selective. - Keywords: Bamberger reaction; Hydrogen fluoride; Mild reductive metals; Fluoroaromatic amines; NMR spectroscopy
- Tordeux, Marc,Wakselman, Claude
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p. 251 - 254
(2007/10/03)
-
- Useful electrophilic trifluoromethylating agents; S-, Se- and Te-(trifluoromethyl)dibenzo-thio-, -seleno- and -telluro-phenium-3-sulfonates
-
S, Se- and Te-(Trifluoromethyl)dibenzo-thio-, -seleno- and -telluro-phenium-3-sulfonates and their dimethyl and nitro derivatives have been synthesized in good yield by sulfonation of the corresponding (trifluoromethyl)dibenzocyclic chalcogen salts with fuming sulfuric acid or by sulfonation followed by nitration.The practical use of these power-variable trifluoromethylating agents has been demonstrated.Thus, they provide good yields of trifluoromethylated products, and the by-product (a salt of dibenzothiophene-3-sulfonic acid or an analog) was easily removed from the products by filtration or by washing with water.S-(Perfluoro-ethyl, -n-butyl- and -n-octyl)dibenzothiophenium-3 sulfonates have also been synthesized and a similar perfluoroalkylation using one of them has been accomplished. - Keywords: Electrophilic trifluoromethylating agents; Perfluoroalkylation; S-(Trifluoromethyl)dibenzothiophenium sulfonates; Se-(Trifluoromethyl)-dibenzoselenophenium sulfonates; Te-(Trifluoromethyl)dibenzotellurophenium sulfonates; NMR/IR spectroscopy
- Umemoto, Teruo,Ishihara, Sumi,Adachi, Kenji
-
-
- Process for preparing amines
-
Process for preparing amines by reacting amides in aqueous-alkaline solutions and/or suspensions with halogens or hypohalites in the presence of alcohols, and converting the reaction products into the amines by hydrolysis, hydrogenation or reductive methods.
- -
-
-
- Pigment compositions for solvent and water-based ink systems and the methods for producing them
-
This invention is an azo pigment composition containing a water insoluble metal salt of a water soluble polymer; a method of preparing said composition and ink compositions prepared from said azo pigment compositions.
- -
-
-
- TRIFLUOROMETHYLATION OF AROMATIC AMINO AND THIO COMPOUNDS BY BISTRIFLUOROMETHYL TELLURIDE
-
The reaction of aromatic and heterocyclic amines with (CF3)2Te gave the products from trifluoromethylation in the aromatic ring.The reaction with the corresponding thiols gave S-trifluoromethyl derivatives.
- Naumann, D.,Pazenok, S. V.,Turra, V.
-
p. 128 - 130
(2007/10/02)
-
- Power-variable electrophilic trifluoromethylating agents. S-, Se-, and Te-(trifluoromethyl)dibenzothio-, -seleno-, and -tellurophenium salt system
-
S-, Se-, and Te-trifluoromethylated dibenzoheterocyclic onium salts, their derivatives, and related salts were synthesized by the direct fluorination of a mixture of 2-[(trifluoromethyl)thio- or seleno]biphenyls and triflic acid (TfOH) or HBF4 etherate, by treatment of the corresponding sulfoxides and selenoxides with Tf2O, by a new type of tellurium activation of 2-[(trifluoromethyl)telluro]biphenyl with Tf2O and (CH3)2SO, or by derivation from the onium salts obtained. Examination of reactivity indicated the trifluoromethyl heterocyclic salts to be greatly reactive compared to nonheterocyclic salts and indicated that this heterocyclic salt system serves as a source of widely applicable trifluoromethylating agents. Their capacity to function as such varied remarkably and increased in the order of Te 2 2. For mixed heterocyclic salts, the orders differed, apparently being determined by the electron deficiency of the CF3 group due to the electron-withdrawing or -donating effects of chalcogens and ring substituents, rather than the inherent nature of the chalcogens. Because of this variation, it was possible to trifluoromethylate a wide range of nucleophilic substrates differing in reactivity: carbanions, activated aromatics, heteroaromatics, enol silyl ethers, enamines, phosphines, thiolate anions, and iodide anions. The reaction mechanism is discussed, and a bimolecular ionic substitution mechanism competing with a free CF3 radical chain mechanism is proposed. Thus, a new field, electrophilic trifluoromethylation, has been established by the present study.
- Umemoto, Teruo,Ishihara, Sumi
-
p. 2156 - 2164
(2007/10/02)
-
- Azo pigment compositions and process for their preparation
-
This invention is that of an azo pigment composition containing about 1 to 10 percent by weight of a nonionic alkyl polyglycoside dispersing agent. The polyglycosides useful in the invention have the general formulae: wherein: M is an oxygen, sulfur, nitrogen phosphorous or silicon atom; n is an integer from 8 to 18, preferably 8 to 11 and X represents the number average degree of polymerization having a numerical value from about 1 to about 2. These azo pigment compositions are prepared by conducting the azo pigment coupling reaction in the presence of said alkyl polyglycoside. The resulting pigment exhibit superior application properties in water based ink systems.
- -
-
-
- Reactions of Trifluoromethyl Bromide and Related Halides: Part 10. Perfluoroalkylation of Aromatic Compounds induced by Sulphur Dioxide Radical Anion Precursors
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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
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p. 2293 - 2299
(2007/10/02)
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- Power-variable trifluoromethylating agents, (trifluoromethyl)dibenzothio- and -selenophenium salt system
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(Trifluoromethyl)dibenzothio- and -selenophenium triflates and their nitro derivatives differing in trifluoromethylating power were developed as a new system of electrophilic trifluoromethylating agents.
- Umemoto,Ishihara
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p. 3579 - 3582
(2007/10/02)
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- Reduction of Aromatic Nitro Compounds with Baker's Yeast
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The reduction of the nitro group of aromatic nitro compounds with baker's yeast was strongly influenced by the nature of the substituent on nitrobenzene, and in the reaction of acyl nitrobenzenes, selective reduction occurred to give optically active nitro alcohol and amino alcohol and amino ketone without giving any amino alcohol.Keywords baker's yeast; nitro compound; selective reduction; acyl nitrobenzene; chiral nitro alcohol
- Takeshita, Mitsuhiro,Yoshida, Sachiko,Kiya, Rieko,Higuchi, Naoko,Kobayashi, Yumi
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p. 615 - 617
(2007/10/02)
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- Perfluoroalkylation of Anilines in the Presence of Zinc and Sulphur Dioxide
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Arylamines are transformed into their ortho- and para-trifluoromethyl derivatives by the action of trifluoromethyl bromide under slight pressure in the presence of 0.15 equiv. of zinc and sulphur dioxide in dimethylformamide.
- Wakselman, Claude,Tordeux, Marc
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p. 1701 - 1703
(2007/10/02)
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- Preparation of ortho-(alkylthiomethyl) anilines by catalytic sulfilimine rearrangement
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This invention relates to a process for preparing ortho-(alkylthiomethyl) anilines by catalytic rearrangement of aromatic sulfilimines in an inert organic solvent. The sulfilimine can be prepared using any of the procedures available in the art. This invention particularly relates to a new class of sulfilimine rearrangement catalysts.
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- 3H-Azepines and Related Systems. Part 2. The Photolyses of Aryl Azides Bearing Electron-withdrawing Substituents
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The photolyses of ortho-substituted aryl azides (o-XC6H4N3 where X = CONHNH2, CONHN=CHAr, NO2, CN, CF3, SO2OMe, SO2NH2, or SO2Ph) in methanol-tetrahydrofuran solution are described.With X = CF3 or CONHN=CHAr, 3-substituted 2-methoxy-3H-azepines are products, while in other cases polymeric products, amines or mixtures of isomeric azepines are obtained.The product from the photolysis of o-azidophenyl phenyl sulphoxide (X = SOPh) is identified tentatively (n.m.r. evidence) as 7-methoxy-2-phenylsulphinyl-3H-azepine.In contrast, methyl p-azidobenzoate and p-cyanophenyl azide yield the corresponding 5-substituted 2-methoxy-3H-azepines, whereas methyl m-azidobenzoate yields only methyl 2-methoxy-3H-azepine-6-carboxylate.Irradiation of methyl o-azidobenzoate in aqueous tetrahydrofuran gives 1,3-dihydro-3-methoxycarbonyl-2H-azepin-2-one.
- Purvis, Roger,Smalley, Robert K.,Suschitzky, Hans,Alkhader, Mohamed A.
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p. 249 - 254
(2007/10/02)
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- Substituent effects on the spectral behavior and synthesis of mercury 1,5-diarylthiocarbazonates
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Symmetric and unsymmetric substituted 1,5-diarylthiocarbazones, and their mono- and bismercury complexes, were synthesized for spectral analysis.The first singlet-singlet transition of the mercury complexes was determined and the spectral shift produced by trifluoromethyl substitution was compared with that caused by different substituents in similar complexes.The large magnitude of the hypsochromic shift produced by the trifluoromethyl substituent can be explained by concerted steric and inductive effects, while the smaller bathochromic shift induced by the methoxy substituent is a result of opposing steric and electronic effects.In the trifluoromethyl substitution, a hypsochromic shift caused by steric influences was found to be 500 cm-1 in the photochromic unactivated state, and 250 cm-1 in the photochromic activated state.A similar shift caused by inductive influences was found to be 750 cm-1 in the photochromic unactivated state, and 600 cm-1 in the photochromic activated state.The smaller spectral shift observed in the photochromic activated state is consistent with the elucidated structure of the unsymmetric 1,5-diarylthiocarbazone, 6d, which was shown that the trifluoromethyl substitution was on the phenylazo portion of the molecule by chemical and spectral studies.
- Chu, Nori Y. C.,Goldstein, Steven A.,Keehn, Philip M.
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p. 679 - 687
(2007/10/02)
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- Pharmaceutical compositions and method of inhibiting phenylethanolamine N-methyltransferase
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Pharmaceutical compositions and methods of inhibiting phenylethanolamine N-methyltransferase using 2-indanamine compounds having 4 and/or 5 substituents.
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- Homogeneous ruthenium catalysts useful in the reduction of ortho-substituted nitroaromatics to amines
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This invention concerns the use of solubilized ruthenium-containing complexes in combination with quaternary ammonium hydroxides to effect the catalytic hydrogenation of certain classes of ortho-substituted mononitroaromatic substrates to their corresponding aryl amines.
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- Method for dehalogenating aromatic compounds
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Dehalogenation of water-immiscible or sparingly soluble aromatic compounds containing chlorine or bromine by contacting with an aqueous solution of a formic acid salt in presence of a hydrogenation catalyst and a surface active agent.
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