- Selective fluorodenitration of chloronitroaromatics
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Nucleophilic fluorination of chloronitrobenzenes shows a strong bias for fluorodenitration rather than halogen exchange.
- Beaumont, Andrew J.,Clark, James H.,Boechat, Nubia A.
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- Fluorodenitrations using Tetramethylammonium Fluoride
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Tetramethylammonium fluoride activated by azeotropic drying in situ is an efficient reagent for the fluorodenitration of nitroaromatics.
- Boechat, Nubia,Clark, James H.
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- Mild and general methods for the palladium-catalyzed cyanation of aryl and heteroaryl chlorides
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New methods for the palladium-catalyzed cyanation of aryl and heteroaryl chlorides have been developed, featuring sterically demanding, electron-rich phosphines. Highly challenging electron-rich aryl chlorides, in addition to electron-neutral and electron-deficient substrates, as well as nitrogen- and sulfur-containing heteroaryl chlorides can all undergo efficient cyanation under relatively mild conditions using readily available materials. In terms of substrate scope and temperature, these methods compare very favorably with the state-of-the-art cyanations of aryl chlorides.
- Littke, Adam,Soumeillant, Maxime,Kaltenbach III, Robert F.,Cherney, Robert J.,Tarby, Christine M.,Kiau, Susanne
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- Catalytic Hydrodefluorination via Oxidative Addition, Ligand Metathesis, and Reductive Elimination at Bi(I)/Bi(III) Centers
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Herein, we report a hydrodefluorination reaction of polyfluoroarenes catalyzed by bismuthinidenes, Phebox-Bi(I) and OMe-Phebox-Bi(I). Mechanistic studies on the elementary steps support a Bi(I)/Bi(III) redox cycle that comprises C(sp2)-F oxidative addition, F/H ligand metathesis, and C(sp2)-H reductive elimination. Isolation and characterization of a cationic Phebox-Bi(III)(4-tetrafluoropyridyl) triflate manifests the feasible oxidative addition of Phebox-Bi(I) into the C(sp2)-F bond. Spectroscopic evidence was provided for the formation of a transient Phebox-Bi(III)(4-tetrafluoropyridyl) hydride during catalysis, which decomposes at low temperature to afford the corresponding C(sp2)-H bond while regenerating the propagating Phebox-Bi(I). This protocol represents a distinct catalytic example where a main-group center performs three elementary organometallic steps in a low-valent redox manifold.
- Cornella, Josep,Katzenburg, Felix,Leutzsch, Markus,N?thling, Nils,Pang, Yue
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supporting information
p. 12487 - 12493
(2021/08/30)
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- Development and Molecular Understanding of a Pd-Catalyzed Cyanation of Aryl Boronic Acids Enabled by High-Throughput Experimentation and Data Analysis
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A synthetic method for the palladium-catalyzed cyanation of aryl boronic acids using bench stable and non-toxic N-cyanosuccinimide has been developed. High-throughput experimentation facilitated the screen of 90 different ligands and the resultant statistical data analysis identified that ligand σ-donation, π-acidity and sterics are key drivers that govern yield. Categorization into three ligand groups – monophosphines, bisphosphines and miscellaneous – was performed before the analysis. For the monophosphines, the yield of the reaction increases for strong σ-donating, weak π-accepting ligands, with flexible pendant substituents. For the bisphosphines, the yield predominantly correlates with ligand lability. The applicability of the designed reaction to a wider substrate scope was investigated, showing good functional group tolerance in particular with boronic acids bearing electron-withdrawing substituents. This work outlines the development of a novel reaction, coupled with a fast and efficient workflow to gain understanding of the optimal ligand properties for the design of improved palladium cross-coupling catalysts.
- De Jesus Silva, Jordan,Bartalucci, Niccolò,Jelier, Benson,Grosslight, Samantha,Gensch, Tobias,Schünemann, Claas,Müller, Bernd,Kamer, Paul C. J.,Copéret, Christophe,Sigman, Matthew S.,Togni, Antonio
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- Metal-free HNO3/TEMPO-catalyzed conversion of benzyl alcohols to aromatic nitriles with oxygen molecule as the terminal oxidant
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A non-metal catalytic method for the aerobic conversion of primary alcohols to aromatic nitriles via a single-step operation was developed. A series of primary benzyl alcohols underwent this transformation to give the targeted products in moderate to high yields under the catalysis of TEMPO/ HNO3.
- Zhao, Bo,Ren, Yun-Lai,Ren, Fangping,Tian, Xinzhe,Zhao, Shuang
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supporting information
p. 627 - 632
(2019/05/01)
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- A process for preparing 2, 4 - difluoro phenyl nitrile (by machine translation)
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The invention discloses a 2, 4 - difluoro phenyl nitrile preparation process, steps are as follows: (1) to 2, 4 - difluoro-benzoic acid and thionyl chloride as the raw material, produced by the reaction of 2, 4 - difluoro-benzoyl chloride; (2) the 2, 4 - difluoro-benzoyl chloride with ammonia water reaction, generating 2, 4 - difluoro-benzamide; (3) the 2, 4 - difluoro-benzamide with trifluoroacetic anhydride reaction, namely the preparation of the 2, 4 - difluoro phenyl nitrile. The invention relates to 2, 4 - difluoro phenyl nitrile synthetic reaction raw materials and synthetic route optimized design, the present invention adopted in the reaction raw material is cheap, it is safe to use; mild reaction conditions, does not need high temperature reaction, low requirements on the equipment, the yield of the product is high, high purity, easy to realize industrial production. (by machine translation)
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Paragraph 0039; 0046; 0047; 0050; 0053
(2019/01/08)
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- Photoinduced Copper(I)-Catalyzed Cyanation of Aromatic Halides at Room Temperature
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The first photoinduced copper(I)-catalyzed cyanation of aromatic halides at room temperature has been developed. The sp2 cyanation reaction exhibits outstanding tolerance to functional groups including primary amines and carboxylic acids, and chemoselectivity to SN2-reactive alkyl chlorides. Mechanistic investigations indicate that the reaction occurs via a single-electron transfer (SET) between the aryl halide and an excited copper(I) cyanide catalytic intermediate. (Figure presented.).
- Kim, Kicheol,Hong, Soon Hyeok
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supporting information
p. 2345 - 2351
(2017/07/22)
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- Design and Synthesis of Novel 4-Phenoxyquinolines Bearing 3-Hydrosulfonylacrylamido or 1H-Imidazole-4-carboxamido Scaffolds as c-Met Kinase Inhibitors
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A series of novel 6,7-disubstituted-4-phenoxyquinoline derivatives bearing (E)-3-hydrosulfonylacrylamido or 1H-imidazole-4-carboxamido moieties were designed, synthesized and evaluated for their cytotoxicity against A549, MKN-45, and HT-29 cancer cell lines in vitro. All the target compounds showed moderate to significant cytotoxic activity against the tested cells with IC50 values ranging from 0.13 to 2.65 μM. Five of them were further examined for their inhibitory activity against c-Met kinase, which identified compound 30 as a promising agent (c-Met IC50 = 1.52 nM) with IC50 values of 0.24, 0.45, and 0.13 μM against HT-29, MKN-45, and A549 cells, respectively.
- Wang, Jiao,Xie, Lijun,Wang, Yu,Wang, Xiaoqiang,Xi, Shuancheng,Zeng, Tianfang,Gong, Ping,Zhai, Xin
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- A 4, 6 - double-halogenated isophthalonitrile preparation method (by machine translation)
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The present invention relates to the technical field of the synthesis of pharmaceutical intermediates, in particular to a 4, 6 - double-halogenated isophthalonitrile preparation method, through the use of cheap and easily obtained 2, 4 - double-halo benzoic acid as the raw material, the reaction of the halide, the amidation reaction, dehydration reaction, the nitration reaction, reduction reaction, the diazotization reaction, the substitution reaction for the synthesis of 4, 6 - double-halogenated isophthalonitrile; the total yield can be 21.5%. The process route is easily obtained and cheap materials, few by-products, the purification treatment is the process is simple, easy to realize industrial production. (by machine translation)
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Paragraph 0104; 0105; 0136; 0137
(2017/07/21)
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- Sulfate additives generate robust and highly active palladium catalysts for the cyanation of aryl chlorides
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The use of sulfate additives such as H2SO4 greatly increases the reactivity of palladium catalysts for the cyanation of aryl and heteroaryl chlorides and renders them more robust toward adventitious air. Using this method, a wide variety of aromatic and heteroaromatic nitriles were prepared in high yield.
- Shevlin, Michael
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experimental part
p. 4833 - 4836
(2010/10/02)
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- Improving palladium-catalyzed cyanation of aryl halides: Development of a state-of-the-art methodology using potassium hexacyanoferrate(II) as cyanating agent
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Benzonitriles are easily accessible via palladium-catalyzed cyanation of aryl halides using potassium hexacyanoferrate(II) as cyanide source. This method is applicable on both activated and deactivated aryl and heteroaryl bromides and activated chlorides giving the corresponding benzonitriles in good to excellent yield. Advantageously, the used cyanating agent is non-toxic and cheap. The presented catalyst system is rather simple and it is not necessary to add expensive phosphines, making the novel method also attractive for industrial applications. Benzonitriles are easily accessible via palladium-catalyzed cyanation of aryl halides using potassium hexacyanoferrate(II) as cyanide source. This method is applicable on both activated and deactivated aryl and heteroaryl bromides and activated chlorides giving the corresponding benzonitriles in good to excellent yield. Advantageously, the used cyanating agent is non-toxic and cheap. The presented catalyst system is rather simple and it is not necessary to add expensive phosphines, making the novel method also attractive for industrial applications.
- Schareina, Thomas,Zapf, Alexander,Beller, Matthias
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p. 4576 - 4583
(2007/10/03)
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- Potassium hexacyanoferrate(II) - A new cyanating agent for the palladium-catalyzed cyanation of aryl halides
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A new advantageous cyanating agent, potassium hexacyanoferrate(II), is described for the palladium-catalyzed cyanation of aryl halides. All cyanide ions on the iron(II) center can be transferred to the aryl halide using palladium(II) acetate and dppf as the catalyst. Under optimized reaction conditions good yields of benzonitriles and unprecedented catalyst productivities are observed.
- Schareina, Thomas,Zapf, Alexander,Beller, Matthias
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p. 1388 - 1389
(2007/10/03)
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- Progress in the palladium-catalyzed cyanation of aryl chlorides
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The development of new palladium catalysts for the cyanation of various aryl and heteroaryl chlorides is described. The combination of amine co-catalysts with chelating phosphine ligands, for example, 1,4-bis(diphenylphosphino)butane (dppb) or 1,5-bis(diphenylphosphino)pentane (dpppe), allows an efficient cyanation of chloroarenes with simple potassium cyanide. General palladium-catalyzed cyanation of nonactivated and deactivated chloroarenes is possible for the first time. Studies of the oxidative addition of aryl halides to palladium triphenylphosphine complexes in the presence and absence of amines suggest that the co-catalyst is capable of preventing catalyst deactivation caused by the presence of excess cyanide ions in solution.
- Sundermeier, Mark,Zapf, Alexander,Mutyala, Sateesh,Baumann, Wolfgang,Sans, Juergen,Weiss, Stefan,Beller, Matthias
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p. 1828 - 1836
(2007/10/03)
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- N-indazolyl[1,2,4]triazolo[1,5-C]pyrimidine-2-sulfonamide herbicides
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Substituted N-indazolyl[1,2,4]triazolo[1,5]-c-pyrimidine-2-sulfonamide compounds, such as N-(4-fluoro-1-methyl-3-indazolyl)-5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine-2-sulfonamide, were prepared by condensation of a 2-chlorosulfonyl[1,2,4]triazolo[1,5-c]pyrimidine compound, such as 2-chlorosulfonyl-5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine, with a substituted 3-aminoindazole compound, such as 3-amino-4-fluoro-1-methylindazole, and found to possess herbicidal utility.
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