- On-Demand Generation and Use in Continuous Synthesis of the Ambiphilic Nitrogen Source Chloramine
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Herein, we demonstrate the on-demand synthesis of chloramine from aqueous ammonia and sodium hypochlorite solutions, and its subsequent utilization as an ambiphilic nitrogen source in continuous-flow synthesis. Despite its advantages in cost and atom economy, chloramine has not seen widespread use in batch synthesis due to its unstable and hazardous nature. Continuous-flow chemistry, however, provides an excellent platform for generating and handling chloramine in a safe, reliable, and inexpensive manner. Unsaturated aldehydes are converted to valuable aziridines and nitriles, and thioethers are converted to sulfoxides, in moderate to good yields and exceedingly short reaction times. In this telescoped process, chloramine is generated in situ and immediately used, providing safe and efficient conditions for reaction scale-up while mitigating the issue of its decomposition over time.
- Danahy, Kelley E.,Styduhar, Evan D.,Fodness, Aria M.,Heckman, Laurel M.,Jamison, Timothy F.
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Read Online
- Efficient nitriding reagent and application thereof
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The invention discloses an efficient nitriding reagent and application thereof, wherein the nitriding reagent comprises nitrogen oxide, an active agent, a reducing agent and an organic solvent. By applying the nitriding reagent, nitrogen-containing compounds such as amide, nitrile and the like can be produced, and the method is simple in condition, low in waste discharge amount and simple in reaction equipment.
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Paragraph 0252-0255
(2021/03/31)
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- Visible-Light-Promoted Metal-Free Synthesis of (Hetero)Aromatic Nitriles from C(sp3)?H Bonds**
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The metal-free activation of C(sp3)?H bonds to value-added products is of paramount importance in organic synthesis. We report the use of the commercially available organic dye 2,4,6-triphenylpyrylium tetrafluoroborate (TPP) for the conversion of methylarenes to the corresponding aryl nitriles via a photocatalytic process. Applying this methodology, a variety of cyanobenzenes have been synthesized in good to excellent yield under metal- and cyanide-free conditions. We demonstrate the scope of the method with over 50 examples including late-stage functionalization of drug molecules (celecoxib) and complex structures such as l-menthol, amino acids, and cholesterol derivatives. Furthermore, the presented synthetic protocol is applicable for gram-scale reactions. In addition to methylarenes, selected examples for the cyanation of aldehydes, alcohols and oximes are demonstrated as well. Detailed mechanistic investigations have been carried out using time-resolved luminescence quenching studies, control experiments, and NMR spectroscopy as well as kinetic studies, all supporting the proposed catalytic cycle.
- Murugesan, Kathiravan,Donabauer, Karsten,K?nig, Burkhard
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supporting information
p. 2439 - 2445
(2020/12/07)
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- A convenient reagent for the conversion of aldoximes into nitriles and isonitriles
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For the dehydroxylation of aldoximes with 4-nitro-1-((trifluoromethyl)sulfonyl)-imidazole (NTSI), slight modifications of reaction conditions resulted in significantly different reaction paths to provide either nitriles or isonitriles. The challenging conversion of aldoximes into isonitriles was achieved under mild conditions.
- Zhang, Wei,Lin, Jin-Hong,Zhang, Pengfei,Xiao, Ji-Chang
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supporting information
p. 6221 - 6224
(2020/06/29)
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- Difluorocarbene-Based Cyanation of Aryl Iodides
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A large number of efficient cyanation methods have been developed because of the wide range of applications of nitriles, but conventional methods usually suffer from the need for a toxic cyanation reagent. Although difluorocarbene chemistry has received increasing attention, the use of difluorocarbene as a sources of the nitrile carbon for nitrile groups remains largely unexplored. We describe a difluorocarbene-based cyanation of aryl iodides promoted by a cheap copper source, Cu(NO 3) 2 ·2.5H 2 O, under an air atmosphere. Ph 3 P + CF 2 CO 2-, an easily available and shelf-stable difluorocarbene reagent, and NaNH 2 are used as the carbon source and the nitrogen source for the nitrile group, respectively. The cyanation protocol is attractive because no toxic reagent is used and performing the reactions under an air atmosphere is operationally convenient.
- Cao, Yu-Cai,Du, Ruo-Bing,Fu, Zhi-Hong,Guo, Yu,Lin, Jin-Hong,Xiao, Ji-Chang,Xiao, Xuan,Yao, Xu,Zhang, Yin-Xiang,Zheng, Xing
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supporting information
p. 713 - 717
(2020/04/08)
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- Method for converting aromatic aldehyde into aromatic nitrile by using sulfur powder promoted inorganic ammonium as nitrogen source (by machine translation)
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The invention discloses a method for converting aromatic aldehyde into aromatic nitrile. The method is conversion of high yield of aromatic aldehyde one-pot reaction of sulfur powder promoted inorganic ammonium as a nitrogen source into aromatic nitrile. The method has the advantages of no need of metal participation, no need of strong oxide, compatibility of reaction to air, easiness in amplification to a gram scale and the like, and overcomes the problems of harsh reaction conditions, complex operation, low functional group compatibility and the like in the prior art. (by machine translation)
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Paragraph 0082; 0083
(2020/09/12)
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- Nitromethane as a nitrogen donor in Schmidt-type formation of amides and nitriles
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The Schmidt reaction has been an efficient and widely used synthetic approach to amides and nitriles since its discovery in 1923. However, its application often entails the use of volatile, potentially explosive, and highly toxic azide reagents. Here, we report a sequence whereby triflic anhydride and formic and acetic acids activate the bulk chemical nitromethane to serve as a nitrogen donor in place of azides in Schmidt-like reactions. This protocol further expands the substrate scope to alkynes and simple alkyl benzenes for the preparation of amides and nitriles.
- Jiao, Ning,Liu, Jianzhong,Qiu, Xu,Song, Song,Wei, Jialiang,Wen, Xiaojin,Zhang, Cheng,Zhang, Ziyao
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supporting information
p. 281 - 285
(2020/01/28)
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- Ni-Catalyzed Reductive Cyanation of Aryl Halides and Phenol Derivatives via Transnitrilation
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Herein, we report a Ni-catalyzed reductive coupling for the synthesis of benzonitriles from aryl (pseudo)halides and an electrophilic cyanating reagent, 2-methyl-2-phenyl malononitrile (MPMN). MPMN is a bench-stable, carbon-bound electrophilic CN reagent that does not release cyanide under the reaction conditions. A variety of medicinally relevant benzonitriles can be made in good yields. Addition of NaBr to the reaction mixture allows for the use of more challenging aryl electrophiles such as aryl chlorides, tosylates, and triflates. Mechanistic investigations suggest that NaBr plays a role in facilitating oxidative addition with these substrates.
- Mills, L. Reginald,Graham, Joshua M.,Patel, Purvish,Rousseaux, Sophie A. L.
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supporting information
p. 19257 - 19262
(2019/12/02)
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- A method for preparing of the benzonitrile derivatives
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The invention discloses a preparation method of a cyanobenzene derivative. The cyanobenzene derivative is prepared by taking phenylacetic acid or the derivative thereof as well as urea as raw materials, copper salt as a catalyst and oxygen as an oxidizing agent. According to the preparation method disclosed by the invention, by adopting copper salt as the catalyst and oxygen as the oxidizing agent without an extra cocatalyst, the raw materials phenylacetic acid or the derivative thereof are easy to purchase in the market, low in cost and various in type, and urea as the source of cyanogen is low in toxicity, low in price, mild in reaction condition and environmentally friendly, and has a good functional group compatibility.
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Paragraph 0021; 0022; 0023; 0054; 0058; 0059; 0060
(2016/10/17)
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- Aryl Nitriles from Alkynes Using tert -Butyl Nitrite: Metal-Free Approach to C≡C Bond Cleavage
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Alkyne C≡C bond breaking, outside of alkyne metathesis, remains an underdeveloped area in reaction discovery. Recently, nitrogenation has been reported to allow nitrile formation from alkynes. A new protocol for the metal-free C≡C bond cleavage of terminal alkynes to produce nitriles is reported. This method provides an opportunity to synthesize a vast range of nitriles containing aryl, heteroaryl, and natural product derivatives (38 examples). In addition, the potential of tBuONO to act as a powerful nitrogenating agent for terminal aryl alkynes is demonstrated. (Figure Presented).
- Dutta, Uttam,Lupton, David W.,Maiti, Debabrata
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supporting information
p. 860 - 863
(2016/03/01)
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- Improved schmidt conversion of aldehydes to nitriles using azidotrimethylsilane in 1,1,1,3,3,3-Hexafluoro-2-Propanol
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The Schmidt reaction of aromatic aldehydes using a substoichiometric amount (40 mol %) of triflic acid is described. Low catalyst loading was enabled by a strong hydrogen-bond-donating solvent hexafluoro-2-propanol (HFIP). This improved protocol tolerates a broad scope of aldehydes with diverse functional groups and the corresponding nitriles were obtained in good to high yields without the need for aqueous work up.
- Motiwala, Hashim F.,Yin, Qin,Aubé, Jeffrey
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- Erratum: Copper-mediated cyanation of indoles and electron-rich arenes using DMF as a single surrogate (Org. Biomol. Chem. (2015) 13 (8322-8329))
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Correction for 'Copper-mediated cyanation of indoles and electron-rich arenes using DMF as a single surrogate' by Lianpeng Zhang et al., Org. Biomol. Chem., 2015, 13, 8322-8329.
- Zhang, Lianpeng,Lu, Ping,Wang, Yanguang
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p. 1840 - 1840
(2016/02/09)
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- Facile one-pot transformation of arenes into aromatic nitriles under metal-cyanide-free conditions
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Electron-rich arenes bearing methyl or methoxy groups on the aromatic ring were treated with dichloromethyl methyl ether and ZnBr2, and then with molecular iodine and aq. ammonia to give the corresponding aromatic nitriles in good yields. Using this method, febuxostat was efficiently prepared from 4-bromophenol in four steps. The method can be used for the preparation of aromatic nitriles from arenes in one pot under metal-cyanide-free conditions. Various electron-rich arenes could be effectively converted into the corresponding aromatic nitriles in good yields, by treatment with ZnBr2 and dichloromethyl methyl ether, followed by reaction with molecular iodine and aq. ammonia.
- Tamura, Toshiyuki,Moriyama, Katsuhiko,Togo, Hideo
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p. 2023 - 2029
(2015/03/18)
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- Copper-mediated cyanation of indoles and electron-rich arenes using DMF as a single surrogate
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The copper-mediated cyanation of indoles with DMF as a single surrogate has been realized. This approach could be applied for the cyanation of some electron-rich arenes and aryl aldehydes as well. Aryl aldehydes were demonstrated to be the key intermediates in the cascade process of cyanation of indoles and electron-rich arenes.
- Zhang, Lianpeng,Lu, Ping,Wang, Yanguang
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p. 8322 - 8329
(2015/08/03)
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- Mild palladium-catalyzed cyanation of (hetero)aryl halides and triflates in aqueous media
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A mild, efficient, and low-temperature palladium-catalyzed cyanation of (hetero)aryl halides and triflates is reported. Previous palladium-catalyzed cyanations of (hetero)aryl halides have required higher temperatures to achieve good catalytic activity. This current reaction allows the cyanation of a general scope of (hetero)aryl halides and triflates at 2-5 mol % catalyst loadings with temperatures ranging from rt to 40 °C. This mild method was applied to the synthesis of lersivirine, a reverse transcriptase inhibitor.
- Cohen, Daniel T.,Buchwald, Stephen L.
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supporting information
p. 202 - 205
(2015/01/30)
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- Copper-catalyzed decarboxylative C≡N triple bond formation: Direct synthesis of benzonitriles from phenylacetic acids under O2 atmosphere
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A copper-catalyzed reaction of phenylacetic acids with urea was found to afford benzonitriles under an oxygen atmosphere. This reaction proceeds smoothly by a sequence of decarboxylation, dioxygen activation, C-H bond functionalization, and nitrile formation with urea as the nitrogen source. Molecular oxygen was found to play a crucial role in this transformation. This reaction represents a novel protocol for the formation of benzonitriles in an environmental friendly way and with good functional group tolerability.
- Feng, Qiang,Song, Qiuling
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supporting information
p. 1697 - 1702
(2014/06/09)
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- Iron(II)-catalyzed direct cyanation of arenes with aryl(cyano)iodonium triflates
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A direct oxidative cyanation of arenes under FeII catalysis with 3,5-di(trifluoromethyl)phenyl(cyano)iodonium triflate (DFCT) as the cyanating agent has been developed. The reaction is applicable to wide range of aromatic substrates, including polycyclic structures and heteroaromatic compounds. Copyright
- Shu, Zhibin,Ji, Wenzhi,Wang, Xi,Zhou, Yujing,Zhang, Yan,Wang, Jianbo
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supporting information
p. 2186 - 2189
(2014/03/21)
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- One-pot transformation of methylarenes into aromatic nitriles with inorganic metal-free reagents
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Various methylarenes were transformed into the corresponding aromatic nitriles in good to moderate yields by the treatment with aq. HBr and aq. H 2O2, followed by reaction with molecular iodine and aq. ammonia in a one-pot procedure. The present reaction is a useful, practical, transition-metal-free, and organic-reagent-free method for the preparation of aromatic nitriles from methylarenes. Various methylarenes were treated with aq. HBr and aq. H2O2 under warming conditions and/or irradiation conditions, followed by the reaction with molecular iodine and aq. ammonia, to provide the corresponding aromatic nitriles, in a one-pot procedure. The present reaction was carried out under metal-free and organic-reagent-free conditions. Copyright
- Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
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p. 4115 - 4122
(2014/07/08)
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- Direct oxidative conversion of methylarenes into aromatic nitriles
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A variety of methylarenes were successfully converted into the corresponding aromatic nitriles in good to moderate yields by the treatment with NBS or DBDMH in the presence of a catalytic amount of AIBN or BPO, followed by the reaction with molecular iodine in aq NH3 in a one-pot procedure. The present reaction is a useful and practical transition-metal-free method for the preparation of aromatic nitriles from methylarenes.
- Tsuchiya, Daisuke,Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
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supporting information
p. 4194 - 4197
(2013/09/12)
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- Schmidt reaction in ionic liquids: Highly efficient and selective conversion of aromatic and heteroaromatic aldehydes to nitriles with [BMIM(SO3H)][OTf] as catalyst and [BMIM][PF6] as solvent
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A mild and selective method is presented for the conversion of aromatic and heteroaromatic aldehydes to nitriles via the Schmidt reaction with TMSN 3 by using [BMIM(SO3H)][OTf] as catalyst and [BMIM][PF6] as solvent. The method offers high yields and simple product isolation, and avoids the use of liquid superacids or corrosive Lewis acids commonly employed for this transformation. It also offers some potential for recycling/reuse of the IL solvent.
- Nandi, Ganesh C.,Laali, Kenneth K.
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p. 2177 - 2179
(2013/04/24)
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- Practical one-pot transformation of electron-rich aromatics into aromatic nitriles with molecular iodine and aq NH3 using Vilsmeier-Haack reaction
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Various electron-rich aromatics could be efficiently transformed into the corresponding aromatic nitriles in good to moderate yields by treatment with DMF and POCl3, followed by the reaction with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH) in aq NH3. Some of less reactive aromatics, such as anisole, 1,2-dimethoxybenzene, 1,4-dimethoxybenzene, and mesityrene, could be also transformed into the corresponding aromatic nitriles in good to moderate yields using N-methylformanilide and O(POCl 2)2, followed by the reaction with molecular iodine in aq NH3. Moreover, propiophenone derivatives could be successfully transformed into the corresponding β-chlorocinnamonitriles by the reaction with DMF and POCl3, followed by the reaction with molecular iodine and aq NH3. These reactions are novel metal-free one-pot methods for the preparation of aromatic nitriles from electron-rich aromatics and β-chlorocinnamonitriles from propiophenones.
- Ushijima, Sousuke,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 4588 - 4595
(2012/07/27)
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- Cyanation of aryl bromides with K4[Fe(CN)6] catalyzed by dichloro[bis{1-(dicyclohexylphosphanyl)piperidine}]palladium, a molecular source of nanoparticles, and the reactions involved in the catalyst-deactivation processes
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Dichloro[bis{1-(dicyclohexylphosphanyl)piperidine}]palladium [(P{(NC 5H10)(C6H11)2}) 2PdCl2] (1) is a highly active and generally applicable C-C cross-coupling catalyst. Apart from its high catalytic activity in Suzuki, Heck, and Negishi reactions, compound 1 also efficiently converted various electronically activated, nonactivated, and deactivated aryl bromides, which may contain fluoride atoms, trifluoromethane groups, nitriles, acetals, ketones, aldehydes, ethers, esters, amides, as well as heterocyclic aryl bromides, such as pyridines and their derivatives, or thiophenes into their respective aromatic nitriles with K4[Fe(CN)6] as a cyanating agent within 24 h in NMP at 140 °C in the presence of only 0.05 mol % catalyst. Catalyst-deactivation processes showed that excess cyanide efficiently affected the molecular mechanisms as well as inhibited the catalysis when nanoparticles were involved, owing to the formation of inactive cyanide complexes, such as [Pd(CN)4]2-, [(CN)3Pd(H)]2-, and [(CN)3Pd(Ar)]2-. Thus, the choice of cyanating agent is crucial for the success of the reaction because there is a sharp balance between the rate of cyanide production, efficient product formation, and catalyst poisoning. For example, whereas no product formation was obtained when cyanation reactions were examined with Zn(CN)2 as the cyanating agent, aromatic nitriles were smoothly formed when hexacyanoferrate(II) was used instead. The reason for this striking difference in reactivity was due to the higher stability of hexacyanoferrate(II), which led to a lower rate of cyanide production, and hence, prevented catalyst-deactivation processes. This pathway was confirmed by the colorimetric detection of cyanides: whereas the conversion of β-solvato-α-cyanocobyrinic acid heptamethyl ester into dicyanocobyrinic acid heptamethyl ester indicated that the cyanide production of Zn(CN)2 proceeded at 25 °C in NMP, reaction temperatures of >100 °C were required for cyanide production with K4[Fe(CN) 6]. Mechanistic investigations demonstrate that palladium nanoparticles were the catalytically active form of compound 1. A balancing act: Compound 1 (see scheme) is a highly active cyanation catalyst. Furthermore, a sharp balance between the rates of cyanide generation, efficient product formation, and catalyst deactivation owing to excess cyanide was observed in deactivation processes. Copyright
- Gerber, Roman,Oberholzer, Miriam,Frech, Christian M.
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supporting information; experimental part
p. 2978 - 2986
(2012/04/04)
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- An expedient Pd/DBU mediated cyanation of aryl/heteroaryl bromides with K4[Fe(CN)6]
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A practical Pd(PPh3)4/DBU catalytic system for the synthesis of pharmaceutically relevant aminopyridine nitrile intermediates, as well as a variety of other aryl nitriles using non-toxic K4[Fe(CN) 6] has been developed. The key features of our new protocol for cyanation lie in that the reaction can be carried out with readily available Pd(PPh3)4 under mild and green conditions, even without the assistance of other ligands. The Royal Society of Chemistry 2012.
- Zhang, Dengyou,Sun, Haifeng,Zhang, Lei,Zhou, Yu,Li, Chunpu,Jiang, Hualiang,Chen, Kaixian,Liu, Hong
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supporting information; experimental part
p. 2909 - 2911
(2012/03/27)
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- A novel and convenient synthesis of benzonitriles: Electrophilic cyanation of aryl and heteroaryl bromides
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N-Cyano-N-phenyl-p-methylbenzenesulfonamide has been used as a more benign electrophilic cyanation reagent for the synthesis of various benzonitriles from (hetero)aryl bromides via formation of Grignard reagents. Electronically different and sterically demanding aryl bromides including functionalized substrates and heteroaryl bromides are successfully cyanated in good to excellent yields. The efficiency of the present methodology is shown by the expeditious syntheses of interesting pharmaceutical intermediates. Notably, chemoselective monocyanation of dibromoarenes is also achieved. Copyright
- Anbarasan, Pazhamalai,Neumann, Helfried,Beller, Matthias
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supporting information; experimental part
p. 4217 - 4222
(2011/05/06)
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- Development of Pd/C-catalyzed cyanation of Aryl halides
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A practical method for palladium-catalyzed cyanation of aryl halides using Pd/C is described. The new method can be applied to a variety of aryl bromide and active aryl chloride substrates to effect efficient conversions. The process features many advantages over existing cyanation conditions and the practical utility of the process has been demonstrated on scale.
- Yu, Hannah,Richey, Rachel N.,Miller, William D.,Xu, Jiansheng,May, Scott A.
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supporting information; experimental part
p. 665 - 668
(2011/03/19)
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- A convenient synthesis of benzonitriles via electrophilic cyanation with N-cyanobenzimidazole
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(Chemical Equation Presented) Couplings: N-Cyanobenzimidazole has been used in the synthesis of aryl- and heteroarylnitriles from the corresponding Grignard reagents (see scheme). This electrophilic cyanation is further extended to the synthesis of 2-cyano1,1'-biaryls through a domino Grignard-coupling/ cyanation strategy.
- Anbarasan, Pazhamalai,Neumann, Helfried,Beller, Matthias
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supporting information; experimental part
p. 4725 - 4728
(2010/07/04)
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- Metal-free one-pot conversion of electron-rich aromatics into aromatic nitriles
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Various electron-rich aromatics could be smoothly converted into the corresponding aromatic nitriles in good to moderate yields by treatment of electron-rich aromatics with POCl3 and DMF, followed by treatment with molecular iodine in aqueous ammonia. The present reaction is a novel metal-free one-pot method for the preparation of aromatic nitriles from electron-rich aromatics.
- Ushijima, Sousuke,Togo, Hideo
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experimental part
p. 1067 - 1070
(2010/06/14)
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- PROCESS FOR PRODUCING 3-ACYLAMINOBENZOFURAN-2-CARBOXYLIC ACID DERIVATIVE
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The present invention provides a process of preparing a compound of the formula [I]: wherein X is a group of the formula: -N="or" -CH=; R1 is a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a cyano group or an amino group optionally substituted by a lower alkyl group; Ring A is a nitrogen-containing heterocyclic group; Ring B is an optionally substituted benzene ring or an optionally substituted pyridine ring; and R3 is a hydrogen atom or a lower alkyl group, or a pharmaceutically acceptable salt thereof , which is useful as an inhibitor of activated blood coagulation factor X.
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Page/Page column 27-28
(2008/06/13)
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- A practical synthesis of highly functionalized aryl nitriles through cyanation of aryl bromides employing heterogeneous Pd/C
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An industrially viable cyanation of aryl bromides with Zn(CN)2 was accomplished in the presence of inexpensive and readily accessible Pd/C, Zn dust, ZnBr2, and PPh3 in DMA to provide functionalized aryl nitriles in moderate to high yields.
- Hatsuda, Masanori,Seki, Masahiko
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p. 1849 - 1853
(2007/10/03)
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- A practical synthesis of highly functionalized aryl nitriles through cyanation of aryl bromides employing heterogeneous Pd/C: In quest of an industrially viable process
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Preparation of aryl nitrile 2a through classical Rosenmund-von Braun reaction of aryl bromide 1a resulted in a poor yield (61%) due to a high reaction temperature (165°C) and a lack of efficient procedure for separating 2a from a large quantity of heavy metal waste (Cu salts). To address these issues, a practical synthesis of multifunctional aryl nitriles through cyanation of aryl bromides has been developed with heterogeneous Pd/C used as the catalyst. Treatment of aryl bromides 1 with Zn(CN)2 in the presence of Pd/C, Zn, ZnBr2 and PPh3 in DMA provided aryl nitriles 2 involving those carrying sterically demanding electron-rich substituent in good yields and in highly reproducible manner. The activity of Pd/C is highly dependent on the properties of the Pd/C. Oxidic thickshell type catalyst Pd/C D5 was found to furnish the highest rate acceleration and yield. The use of heterogeneous Pd/C might anchor and disperse Pd over the solid support of the catalyst, at least in the initial stage of the reaction, to assure the formation of monomeric Pd complex without precipitating to inactive Pd black. The use of a slightly excess of Zn(CN)2 (0.6 equiv) and air oxidation of phosphine ligand, after end of the reaction, converted Pd species to insoluble phosphine-free Pd cyanides, from which Pd was recovered in high yield through simple filtration followed by usual recovery process involving combustion.
- Hatsuda, Masanori,Seki, Masahiko
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p. 9908 - 9917
(2007/10/03)
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- COPPER-CATALYZED FORMATION OF CARBON-HETEROATOM AND CARBON-CARBON BONDS
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One aspect of the present invention relates to copper-catalyzed carbon-heteroatom and carbon-carbon bond-forming methods. In certain embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-sulfur bond between the sulfur atom of a thiol moiety and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In other embodiments, the present invention relates to copper(II)-catalyzed methods of forming a carbon-nitrogen bond between the nitrogen atom of an amide and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In certain embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-carbon bond between the carbon atom of cyanide ion and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In another embodiment, the present invention relates to a copper-catalyzed method of transforming and aryl, heteroaryl, or vinyl iodide. Yet another embodiment of the present invention relates to a tandem method, which may be practiced in a single reaction vessel, wherein the first step of the method involves the copper-catalyzed formation of an aryl, heteroaryl, or vinyl iodide from the corresponding aryl, heteroaryl, or vinyl chloride or bromide; and the second step of the method involves the copper-catalyzed formation of an aryl, heteroaryl, or vinyl nitrile, amide or sulfide from the aryl, heteroaryl, or vinyl iodide formed in the first step.
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- An efficient phosphine-free palladium coupling for the synthesis of new 2-arylbenzo[b]thiophenes
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Straightforward and rapid access to 2-arylbenzo[b]thiophenes has been developed. It involved a catalytic coupling of 3-activated benzo[b]thiophenes with several aryl halides in the presence of a phosphine-free palladium system. In case of fragile functional groups such as aldehydes, a quaternary ammonium was used as an additive as with the other substrates, the coupling performed better and faster in the presence of a crown ether, the best one being DCH-18-C-6, with good yields and low reaction times. This method would provide a direct access to novel structures of biological interest.
- Dit Chabert, Jérémie Fournier,Joucla, Lionel,David, Emilie,Lemaire, Marc
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p. 3221 - 3230
(2007/10/03)
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- Copper-catalyzed domino halide exchange-cyanation of aryl bromides
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An efficient copper-catalyzed domino halogen exchange-cyanation procedure for aryl bromides was developed utilizing 10 mol % CuI, 20 mol % KI, 1.0 equiv of the inexpensive N,N′-dimethylethylenediamine as ligand, and 1.2 equiv of NaCN in toluene at 110 °C. The new method represents a significant improvement over the traditional Rosenmund-von Braun reaction: the reaction conditions are much milder, and the use of stoichiometric amounts of copper(I) cyanide and polar solvents is avoided; therefore the isolation and purification of the aromatic nitrile products is greatly simplified. In addition, the new method exhibits excellent functional group compatibility comparable to that of the analogous Pd-catalyzed cyanation methodology. Copyright
- Zanon, Jacopo,Klapars, Artis,Buchwald, Stephen L.
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p. 2890 - 2891
(2007/10/03)
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- Anodic Cyanation of Benzothiophenes
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The electrooxidation of benzothiophene and 2-methyl- and 3-methyl-benzothiophene was carried out in methanol containing sodium cyanide at a Pt anode in a divided cell.In all instances, heterocyclic ring-substitution products were obtained, together with minor amounts of addition products.With methylbenzothiophene, a small amount of side-chain-methoxylation product was also formed as a by-product.
- Yoshida, Kunihisa,Miyoshi, Kohji
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p. 333 - 336
(2007/10/02)
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- OUVERTURE PAR LES ORGANOLITHIENS D'ISOTHIAZOLES ET ISOSELENAZOLES HETEROCONDENSES
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The ring-opening of bi- and tricyclic systems bearing an isothiazole or isoselenazole ring fused to a thiophene or a selenophene ring was studied by their reaction with methyl lithium.
- Onyamboko, N. V.,Weber, R.,Fauconnier, A.,Renson, M.
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