55406-13-8Relevant academic research and scientific papers
Stable and reusable nanoscale Fe2O3-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides
Murugesan, Kathiravan,Senthamarai, Thirusangumurugan,Sohail, Manzar,Sharif, Muhammad,Kalevaru, Narayana V.,Jagadeesh, Rajenahally V.
supporting information, p. 266 - 273 (2018/01/12)
The sustainable introduction of nitrogen moieties in the form of nitrile or amide groups in functionalized molecules is of fundamental interest because nitrogen-containing motifs are found in a large number of life science molecules, natural products and materials. Hence, the synthesis and functionalization of nitriles and amides from easily available starting materials using cost-effective catalysts and green reagents is highly desired. In this regard, herein we report the nanoscale iron oxide-catalyzed environmentally benign synthesis of nitriles and primary amides from aldehydes and aqueous ammonia in the presence of 1 bar O2 or air. Under mild reaction conditions, this iron-catalyzed aerobic oxidation process proceeds to synthesise functionalized and structurally diverse aromatic, aliphatic and heterocyclic nitriles. Additionally, applying this iron-based protocol, primary amides have also been prepared in a water medium.
A Homogeneous Method for the Conveniently Scalable Palladium- and Nickel-Catalyzed Cyanation of Aryl Halides
Burg, Finn,Egger, Julian,Deutsch, Johannes,Guimond, Nicolas
, p. 1540 - 1545 (2016/08/30)
Homogeneous conditions for the palladium-catalyzed cyanation of aryl halides were developed. This new system features a broad scope of aryl chlorides and bromides, uses 2-propanol or 1-butanol as solvent, and is readily scalable. The same conditions can also provide simple benzonitriles using the recently developed (TMEDA)NiCl(o-tolyl) precatalyst in conjunction with 1,1′-bis(diphenylphosphino)ferrocene (dppf) as a ligand.
Green halogenation of aromatic heterocycles using ammonium halide and hydrogen peroxide in acetic acid solvent
D'Aleo, Danielle N.,Allard, Sheena R.,Foglia, Cassandra C.,Parent, Shawna L.M.,Rohr, David J.,Gottardo, Christine,MacKinnon, Craig D.
, p. 679 - 683 (2013/08/23)
The green generation of X+ (X = Br, I) using hydrogen peroxide in aqueous acetic acid allows access to aromatic heterocyclic halides in yields and purities comparable to syntheses employing N-bromosuccinimide. In activated and unsubstituted thiophene rings, regioselectivity is quantitative for positions α to the sulfur; pyrroles also give quantitative reactions, at least initially. Deactivated rings, including furans and thiazoles, as well as thiophenes with strongly electron-withdrawing groups showed little to no reactivity under the conditions investigated. The reaction shows remarkable functional group tolerance (to alcohol, nitro, alkyl, halo, and carbonyl groups), as shown through reaction with substituted phenols. In all bromination reactions, reaction yields and regiochemistry were very similar to reactions involving N-bromosuccinimide in tetrahydrofuran solvent.
Cyclopropenone-catalyzed direct conversion of aldoximes and primary amides into nitriles
Rai, Ankita,Yadav, Lal Dhar S.
, p. 1889 - 1893 (2013/05/08)
Efficient conversion of aldoximes and primary amides into nitriles by employing cyclopropenone as an organocatalyst is reported. The reaction proceeds smoothly under mild conditions with 5 mol-% catalyst loading to afford nitriles in excellent yields (78-94 %) in a single operation. This method is equally applicable to both aldoximes and primary amides bearing aromatic, heterocyclic, and aliphatic moieties. The convenient and catalytic procedure widens the scope of the utilization of cyclopropenones in organic synthesis. Cyclopropenone- catalyzed conversion of aldoximes and primary amides into nitriles in a one-pot procedure is described. The reaction proceeds smoothly under mild conditions with low catalyst loading. The convenient and catalytic procedure widens the scope of the utilization of cyclopropenones in organic synthesis.
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
Gerber, Roman,Oberholzer, Miriam,Frech, Christian M.
supporting information; experimental part, p. 2978 - 2986 (2012/04/04)
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
ANTIMICROBIAL/ADJUVANT COMPOUNDS AND METHODS
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Page/Page column 66; 67, (2012/09/21)
Among other things, in general, antimicrobial and/or adjuvant compounds are provided according to Formula la: (Ia) in which E and R1-11 have the meanings described herein; and prodrugs and pharmaceutically acceptable salts thereof. Other formulae and methods of use are also provided.
Development of Pd/C-catalyzed cyanation of Aryl halides
Yu, Hannah,Richey, Rachel N.,Miller, William D.,Xu, Jiansheng,May, Scott A.
supporting information; experimental part, p. 665 - 668 (2011/03/19)
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.
Straightforward conversion of arene carboxylic acids into aryl nitriles by palladium-catalyzed decarboxylative cyanation reaction
Ouchaou, Kahina,Georgin, Dominique,Taran, Frédéric
experimental part, p. 2083 - 2086 (2010/10/03)
A one-pot procedure to convert aromatic carboxylic acids into aromatic nitriles is described. The methodology is based on a palladium(II)-catalyzed decarboxylative cyanation reaction using cyanohydrins as soluble cyanide sources. The described reaction worked on a panel of substrates and is additionally of particular interest for the straightforward preparation of 13C- or 14C-labeled compounds.
Hypervalent iodine(III): selective and efficient single-electron-transfer (SET) oxidizing agent
Dohi, Toshifumi,Ito, Motoki,Yamaoka, Nobutaka,Morimoto, Koji,Fujioka, Hiromichi,Kita, Yasuyuki
experimental part, p. 10797 - 10815 (2010/03/01)
In 1994, we first determined the single-electron-transfer (SET) oxidation ability of phenyliodine(III) bis(trifluoroacetate) (PIFA) toward phenyl ethers, affording the corresponding aromatic cation radicals. Since then, hypervalent iodine(III) has been utilized as a selective and efficient SET oxidizing agent that enables a variety of direct C-H functionalizations of aromatic rings in electron-rich arenes under mild conditions. We have now extended the original method to work in a series of heteroaromatic compounds such as thiophenes, pyrroles, and indoles. The investigations and results obtained since the start of this century are summarized in this article.
Mild and general methods for the palladium-catalyzed cyanation of aryl and heteroaryl chlorides
Littke, Adam,Soumeillant, Maxime,Kaltenbach III, Robert F.,Cherney, Robert J.,Tarby, Christine M.,Kiau, Susanne
, p. 1711 - 1714 (2008/02/02)
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.
