- An efficient new procedure for the one-pot conversion of aldehydes into the corresponding nitriles
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A new and efficient procedure for the one-pot conversion of various aldehydes into the corresponding nitriles under mild reaction conditions has been developed. The ethyl dichlorophosphate/DBU-mediated dehydration of aldoxime intermediates was utilized as a key operation to effect the transformation. Georg Thieme Verlag Stuttgart.
- Zhu, Jia-Liang,Lee, Fa-Yen,Wu, Jen-Dar,Kuo, Chun-Wei,Shia, Kak-Shan
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- Synthesis of [5-(1H-1,2,3-triazol-4-yl)-1,3,4-oxadiazol-2-yl]pyridines
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2-, 3-, and 4-[5-(1-Aryl-5-R-1H-1,2,3-triazol-4-yl)-1,3,4-oxadiazol-2-yl] pyridines were synthesized from the corresponding 1-aryl-5-R-1H-1,2,3-triazole- 4-carbonyl chlorides and 2-, 3-, and 4-(1H-tetrazol-5-yl)-pyridines.
- Pokhodylo,Shiika,Matiichuk,Obushak
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- A simple and convenient method for the synthesis of nitriles by oxidation of primary amines with NaOCl in ethanol
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The oxidation of aliphatic primary amines having α-methylene on treatment with NaOCl as an oxidant in ethanol has been found to be an effective method for the transformation of primary amines to nitriles.
- Yamazaki, Shigekazu
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- An efficient one-pot synthesis of nitriles from carboxylic acids without solvent under microwave irradiation
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Nitriles were prepared from alkyl and aryl carboxylic acids in dry media conditions, under microwave irradiation. Heating of the carboxylic acid, urea and amidosulfonic acid adsorbed on alumina support in a microwave oven affords nitriles in 20-93% yields.
- Juncai, Feng,Bin, Liu,Yang, Lhi,Changchuan, Li
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- Deoxygenation of pyridine N-oxides with dimethylthiocarbamoyl chloride
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(Chemical Equation Presented) Treatment of pyridine N-oxides with dimethylthiocarbamoyl chloride in boiling acetonitrile effects chemoselective deoxygenation to pyridines.
- Ponaras, Anthony A.,Zaim, Oemer
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- A mild deoxygenation of heteroaromatic N-oxides by formamidinesulfinic acid
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Various heteroaromatic N-oxides were efficiently deoxygenated to the corresponding bases under mild conditions using formamidinesulfinic acid (thiourea S,S-dioxide).
- Balicki, Roman,Chmielowiec, Urszula
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- Pentacyanoferrates(II): Solvatochromism and Reactivity in Micelles and in Reversed Micelles
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Rate constants for dissociation of pyridine derivatives from pentacyanoferrates(II), (3-), in micelles and in reversed micelles reflect significant interactions between the leaving ligands and the micelle or the water in the interior of the
- Burgess, John,Patei, Marttand S.
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- Efficient and chemoselective deoxygenation of amine N-oxides using polymethylhydrosiloxane
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Deoxygenation of aromatic and aliphatic amine N-oxides to the corresponding amines is achieved under mild conditions. The reagent combination employed for this transformation is polymethylhydrosiloxane (PMHS) in the presence of either tetrakis (triphenylphosphine) palladium (0) [Pd(PPh3)4], titanium (IV) isopropoxide [Ti(i-PrO)4] or palladium on carbon (Pd/C).
- Chandrasekhar,Reddy, Ch. Raji,Rao, R. Jagadeeshwar,Rao, J. Madhusudana
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- Electronic Effects on the Menschutkin Reaction. A Complete Kinetic and Thermodynamic Dissection of Alkyl Transfer to 3- and 4-Substituted Pyridines
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The relationship between kinetic and thermodynamic parameters is explored for quaternization of a series of pyridines (mostly 3- and 4-substituted) with several methylating and ethylating reagents in several solvents.The reaction with methyl iodide in acetonitrile is reversible at temperatures in the neighborhood of 100 deg C so that the effect of substituents on free energy, enthalpy, and entropy for activation of the forward and reverse reactions and for the overall quaternization can be determined.A variety of experimental techniques was used to obtain rates over a range of 1013 and to determine enthalpies and entropies of reaction.The results are self-consistent and agree generally with isolated published values for similar systems.The relationship between thermodynamic and activation parameters is examined, and a gross disparity is found between free energy and enthalpy behavior compared with that of the entropies.A consistent picture of the quaternization reaction emerges, based on many studies using a variety of mechanistic probes.The transition state is "early" as far as bond formation to the base in concerned but "late" in terms of bond rupture between the transferring alkyl group and the leaving group with solvent reorganization nearly complete.Quaternization of the 3- and 4-substituted pyridines does not follow the reactivity-selectivity principle, but that of 2-substituted pyridines does.The current practice of assigning detailed bimolecular structures to transition states for substitution, addition, or elimination reactions by application of the Hammond postulate is criticized in view of its inability to handle the dominating role of solvation dynamics and because of the considerable difference in potential energy content (and therefore structure) between the transition states and the reactants or products.
- Arnett, Edward M.,Reich, Ronald
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- Boryl Radicals-Triggered Selective C-H Functionalization for the Synthesis of Diverse Phenanthridine Derivatives
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A boryl radical-triggered C-H functionalization of aliphatic ethers/amines or DMF with isocyanides is developed to deliver diverse phenanthridine derivatives in good to excellent yields. The substrate scope is broad, and a wide range of functional groups
- Guo, Ao,Han, Jia-Bin,Tang, Xiang-Ying
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- A NEW METHOD FOR DEOXYGENATION OF HETEROAROMATIC N-OXIDES WITH CHLOROTRIMETHYLSILANE/SODIUM IODIDE/ZINC
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Heteroaromatic N-oxides are easily deoxygenated with chlorotrimethylsilane/sodium iodide/zinc in acetonitrile to give the corresponding parent bases in good yields.
- Morita, Tsuyoshi,Kuroda, Koji,Okamoto, Yoshiki,Sakurai, Hiroshi
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- A Novel and Efficient Deoxygenation of Hetero Cyclic N-Oxides Using ZrCl4/NaBH4
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A practical and novel reagent system ZrCl4/NaBH4 is used for the deoxygenation of N-Oxides to amines is described.
- Chary, K. Purushothama,Mohan, G. Hari,Iyengar, D. S.
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- Outer-sphere and inner-sphere processes in organic chemistry. Reaction of trifluoromethyl bromide with electrochemically generated aromatic anion radicals and sulfur dioxide anion radicals
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The reduction of CF3Br by electrochemically generated aromatic anion radicals gives rise to purely catalytic currents. An activation-driving force relationship characterizing outer-sphere electron donors can thus be established. Electrochemically generated sulfur dioxide anion radicals do not give rise to catalytic currents upon reaction with CF3Br but rather produce trifluoromethyl sulfinate according to an overall two electron per molecule stoichiometry. The rate constant of the rate-determining step of the reaction is at least 4 orders of magnitude larger than that of an aromatic anion radical of the same standard potential, unambiguously showing that SO2(·-) does not react as an outer-sphere electron donor. Among the various possible inner-sphere processes, bromine atom abstraction appears as the most likely.
- Andrieux,Gelis,Saveant
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- Highly efficient gold nanoparticle catalyzed deoxygenation of amides, sulfoxides, and pyridine N-oxides
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Selective deoxygenation is one of the most important reactions in the areas of total synthesis, biological chemistry, and transformation of renewable biomass resources.To date, many useful methods for the selective deoxygenation of oxygen-containing organic molecules, such as amides, nitro compounds, epoxides, sulfoxides, and those with Noxide groups, have been developed. However, these methods often include stoichiometric reactions. Some successful catalysts have been reported,but most of them are homogeneous systems and still suffer from low activities and selectivities, harsh reaction conditions, and tedious workup procedures. Therefore, further development of highly efficient heterogeneous catalysts for selective deoxygenations is highly desired.
- Mikami, Yusuke,Noujima, Akifumi,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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- Efficient transformation of aldoximes to nitriles using 2-chloro-1-methylpyridinium iodide under mild conditions
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Various (aliphatic, aromatic, and heterocyclic aromatic) types of aldoximes were converted into the corresponding nitriles in good to excellent yields using 2-chloro-1-methylpyridinium iodide (CMPI) as a dehydrating agent under mild conditions.
- Lee, Kieseung,Han, Sang-Bae,Yoo, Eun-Mi,Chung, Soon-Ryang,Oh, Haibum,Hong, Sungwan
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- Efficient catalytic conversion of pyridine N-oxides to pyridine with an oxorhenium(V) catalyst
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(Equation Presented) The compound CH3Re(O)(SR)2PPh3, where (SR)2 represents the dianion of 2-(mercaptomethyl)thiophenol, catalyzes the rapid and efficient transfer of an oxygen atom from a wide range of ring-substituted pyridine N-oxides to triphenylphosphine, yielding the pyridines in high yield.
- Wang, Ying,Espenson, James H.
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- Catalytic deoxygenation of pyridine N-oxides with N-fused porphyrin rhenium complexes
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Deoxygenation reactions of pyridine N-oxide derivatives catalyzed by N-fused porphyrin rhenium(VII) trioxo complexes are developed, affording the corresponding pyridine derivatives in quantitative yields with excellent turnover numbers up to 340,000.
- Toganoh, Motoki,Fujino, Keitaro,Ikeda, Shinya,Furuta, Hiroyuki
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- Efficient Deoxygenation of Heteroaromatic N-Oxides with Ammonium Formate as a Catalytic Hydrogen Transfer Agent
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Ammonium formate catalytic transfer hydrogenation in the presence of 10percent palladium on carbon has shown utility for mild and excellent deoxygenation of heteroaromatic N-oxides in neutral medium.
- Balicki, Roman
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- Catalyst-Free N-Deoxygenation by Photoexcitation of Hantzsch Ester
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A mild and operationally simple protocol for the deoxygenation of a variety of heteroaryl N-oxides and nitroarenes has been developed. A mixture of substrate and Hantzsch ester is proposed to result in an electron donor-acceptor complex, which upon blue-light irradiation undergoes photoinduced electron transfer between the two reactants to afford the products. N-oxide deoxygenation is demonstrated with 22 examples of functionally diverse substrates, and the chemoselective reduction of nitroarenes to the corresponding hydroxylamines is also shown.
- Cardinale, Luana,Jacobi Von Wangelin, Axel,Konev, Mikhail O.
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- Facile and Efficient Deoxygenation of Amine-N-oxides with Gallium in Water
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A facile and efficient procedure for the deoxygenation of amine-N-oxides with gallium metal in water is described. The experimental procedure is quite simple and the products are obtained in high yields without any activating agent.
- Han, Jung Hwa,Choi, Kyung Il,Kim, Joong Hyup,Yoo, Woo Byung
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- Reactivity of Heterocyclic Nitrogen Donors in Systems containing the Tetrachloroaurate(III) Anion
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A series of gold(III) complexes of the type has been prepared and characterized (L = oxazole, benzoxazole, thiazole, their benzo and methyl-substituted derivatives, or 2-methylbenzoselenazole).The five-membered N.O-, N,S- and N,Se-heterocyclic bases are all bound to Au(III) through nitrogen.The kinetics of the displacement of L by chloride to give (1-) has been studied in methanol-water (95:5. v/v) at 25.0 deg C and I = 0.20 mol dm-3 (LiClO4).The equilibrium constants for the reversible processes have also been determined.The reactions of the corresponding pyridine, 4-chloro-, 4-cyano- and 2,6-bis(chloromethyl)-pyridine complexes have also been reexamined under the same conditions.The equlibrium constants, K2, depend upon the basicity of the nitrogen in the ligands and points for all ligands, irrespective of ring size and composition, lie roughly on the same log K2 versus pKa curve.There is no significant systematic steric effect on the equilibrium constants of the sort found for the more basic methyl pyridines.The complexes of the five-membered heterocyclic ligands are approximately ten times less reactive than those of the six-membered N-heterocycles of comparable basicity and exhibit steric retardation from ortho-methyl substituents.The nucleophilicities of these ligands have been calculated and five-membered N,O- and N,S-heterocycles are considerably less reactive than six-membered N-heterocycles of similar basicity.
- Canovese, Luciano,Cattalini, Lucio,Tomaselli, Michele,Tobe, Martin L.
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- Chemoselective hydrogenation of nitroarenes and deoxygenation of pyridine N-oxides with H2 catalyzed by MoO2Cl2
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A chemoselective and highly efficient hydrogenation of nitroarenes and deoxygenation of pyridine N-oxides using a cheap and environmentally friendly H2/MoO2Cl2 system has been developed.
- Reis, Patrícia M.,Royo, Beatriz
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- Formation and Reaction of Trichloro Complexes of Bivalent Transition Metals in 1,2-Dichloroethane
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Trichloro complexes of some bivalent transition metals (M2+) have been prepared in tetra-n-butylammonium chloride-1,2-dichloroethane solution saturated with the metal chlorides.Their chemical forms and reactions, and the effect of water, have been investigated by means of spectrophotometry and vapour-pressure osmometry at 25.0 deg C.Copper(II) and cadmium(II) form monomeric tetrahedral trichloro complexes containing onoe water molecule, NBu4, whilst cobalt(II) forms a dimeric tetrahedral trichloro complex 2.Zinc(II) exists as a mixture of monomeric and dimeric forms.Manganese(II) and nickel(II) do not form trichloro complexes.Copper(II) forms a monomeric tetrachloro complex.Cobalt(II) forms a monomeric tetrachloro complex and a trichloromono(pyridine base) complex by reaction with NBu4Cl and with pyridine base respectively.The formation constants of the copper(II) and cobalt(II) complexes have been evaluated by means of spectrophotometry.The effect of water on the equilibria of the trichloro complexes of coppoer(II) and cobalt(II) is discussed.
- Satoh, Keiichi,Suzuki, Toshio,Sawada, Kiyoshi
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- Mild and efficient deoxygenation of amine-N-oxides with MoCl5/NaI system
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The MoCl5/NaI system was found to be a new reagent for deoxygenation of various amine-N-oxides to the corresponding amines in good to excellent yields under mild conditions. Copyright Taylor & Francis Group, LLC.
- Yoo, Byung Woo,Park, Min Chol
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- An Efficient Deoxgenation of Heteroaromatic N-Oxides Using Zinc Dust/Ammonium Formate Reagent System
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Heteroaromatic N-oxides were readily and selectively deoxygenated to the corresponding bases with zinc/ammonium formate reagent system.
- Balicki, Roman,Cybulski, Marcin,Maciejewski, Grzegorz
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- An overview on the progress and development on the palladium catalyzed direct cyanation
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Generation of the positive CN ion and the corresponding direct cyanation are both extremely important for cyanation of aromatic compounds. Hereby, we would like to report the simultaneous use of the new Pd nano-catalyst as well as the three types of the N-arylsulfonyl cyanamides (A, B and C) as potent reagents for the in situ generation of the positive CN ion for the direct cyanation of phenylboronic acids in acetonitrile at reflux conditions.
- Heydari, Somayyeh,Habibi, Davood,Reza Faraji, Ali,keypour, Hassan,Mahmoudabadi, Masoumeh
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- Stability studies of bis(pyridiniumaldoxime) reactivators of organophosphate-inhibited acetylcholinesterase
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Relative stability studies of three organophosphate-inhibited acetylcholinesterase reactivators, 1-(2-hydroximinomethyl-1-pyridinium)-3-(4-carbamoyl-1-pyridi nium)-2-oxapropane dichloride (HI-6), 1,1'-methylenebis(4-hydroximinomethylpyridinium) dichloride (MMB-4), and 1,1'-trimethylenebis(4-hydroximinomethylpyridinium) dibromide (TMB-4) were carried out by semiquantitative TLC and NMR methods. TMB-4 appears to be the most, and HI-6 the least stable of the three compounds. The extent of hydrolysis of HI-6, MMB-4, and TMB-4 in 0.05 M, pH 7 phosphate buffer was ~50, 25, and 2O and of the protons at the 2- and 6-positions of the pyridinium ring of TMB-4 in NaOD/D2 were observed.
- Lin,Klayman
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- Facile deoxygenation of amine-N-oxides with CoCl2·6H 2O-indium system
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CoCl2·6H2O/In system was found to be a new reagent for deoxygenation of various amine-N-oxides to the corresponding amines in good to excellent yields under sonication. Copyright Taylor & Francis Group, LLC.
- Jung, Hwa Han,Kyung, Il Choi,Joong, Hyup Kim,Cheol, Min Yoon,Byung, Woo Yoo
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- Interconversion of MeReO(dithiolate)(NC5H4-X) and MeReO(dithiolate)(PAr3) complexes: The equilibrium constants follow the Hammett equation but the rate constants do not
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Equilibration occurs among the species MeReO(dithiolate)Py, MeReO(dithiolate)(PZ3), Py, and PZ3 where the chelating dithiolate ligand is 1,2-ethanedithiol (edt) or 1,3-propanedithiol (pdt), Py stands for NC5H4-4-X and PZ3 for both P(C 6H4-4-Y)3 and P(alkyl)n(Ph) 3-n. Equilibrium constants in the pdt series were evaluated directly; values of K generally favor phosphane coordination and range from 4.8 × 10-2 (X = NMe2, Y = Cl) to 3.2 × 10 4 (X = CN, Y = OMe). The values of K are well correlated by the Hammett equation with ρXK = 2.7(3) and ρ YK = -2.0(3). Kinetic data were determined with the stopped-flow method for 65 reactions of the edt and pdt complexes, and resolved into forward and reverse components by use of the equilibrium constants. Values of kfor, deviate markedly from Hammett behavior, especially along any series with a given X substituent, where plots of log kfor against 3σY take on a V-shaped appearance. This pattern has been interpreted in terms of a two step mechanism for ligand substitution reactions of these complexes. The rate constants for those phosphanes that are the better Lewis bases are governed by Re-P bond formation. The rate constants for those phosphanes that are weaker Lewis bases, on the other hand, are governed by the second step in which an initial ψ-octahedral complex rotates towards a transition state that is an approximate trigonal prism. In so doing, the prior Re-P interaction is weakened, which gives rise to an increase in log kfor with σY.
- Shan, Xiaopeng,Espenson, James H.
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- Efficient Chemoselective Reduction of N-Oxides and Sulfoxides Using a Carbon-Supported Molybdenum-Dioxo Catalyst and Alcohol
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The chemoselective reduction of a wide range of N-oxides and sulfoxides with alcohols is achieved using a carbon-supported dioxo-molybdenum (Mo@C) catalyst. Of the 10 alcohols screened, benzyl alcohol exhibits the highest reduction efficiency. A variety of N-oxide and both aromatic and aliphatic sulfoxide substrates bearing halogens as well as additional reducible functionalities are efficiently and chemoselectively reduced with benzyl alcohol. Chemoselective N-oxide reduction is effected even in the presence of potentially competing sulfoxide moieties. In addition, the Mo@C catalyst is air- and moisture-stable, and is easily separated from the reaction mixture and then re-subjected to reaction conditions over multiple cycles without significant reactivity or selectivity degradation. The high stability and recyclability of the catalyst, paired with its low toxicity and use of earth-abundant elements makes it an environmentally friendly catalytic system.
- Li, Jiaqi,Liu, Shengsi,Lohr, Tracy L.,Marks, Tobin J.
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- Mild and efficient method for the synthesis of nitriles
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The treatment of aldoximes with a mixture of DMAD and triethylamine serve as an efficient and mild method for the synthesis of aromatic and α,β-unsaturated nitriles in high yields at room temperature.
- Coskun, Necdet
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- A Versatile VMPO Catalyst Prepared In Situ for Oxidative Ammonolysis of Isomeric Picolines and Xylenes
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Abstract: The V2O5–MoO3–P2O5 (VMPO) catalyst has been prepared in situ by thermal decomposition of vanado-molybdophosphoric acid (PMoV) on TiO2 support at 475°C. The TiO2 supported VMPO catalysts are characterized by FT–IR, XRD, BET surface area, NH3–TPD, and H2–TPR. Morphology of the catalyst has been studied by TEM. The accumulated data indicate decomposition of PMoV and presence of phosphate and pyrophosphate phases of molybdenum and vanadium after calcination. TPD and TPR studies exhibit the moderate acidity and presence of V4+ in the material, respectively. The VMPO catalyst has been used for ammoxidation of six different compounds including three isomeric picolines and three isomeric xylenes to the corresponding nitriles with the yield of 90–96%.
- Dutta, P.,Pathak, D. D.,Senapati, Rabinarayan
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- Cyclic Hydroxamic Acid Analogues of Bacterial Siderophores as Iron-Complexing Agents prepared through the Castagnoli–Cushman Reaction of Unprotected Oximes
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The first application of multicomponent chemistry (the Castagnoli–Cushman reaction) toward the convenient one-step preparation of cyclic hydroxamic acids is described. Cyclic hydroxamic acids are close analogues of bacterial siderophores (iron-binding com
- Bakulina, Olga,Bannykh, Anton,Dar'in, Dmitry,Krasavin, Mikhail
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- Oxidative ammonolysis of 3- and 4-methylpyridines on vanadium oxide catalysts modified with titanium and tin oxides
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Catalytic properties of vanadium-titanium-tin oxides catalysts of various compositions were studied in oxidative ammonolysis of 3- and 4-methylpyridines. Pleiades Publishing, Ltd., 2012.
- Mikhailovskaya,Yugay,Chukhno,Sembaev
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- Electrochemical Deoxygenation of N-Heteroaromatic N -Oxides
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An electrochemical method for the deoxygenation of N-heteroaromatic N -oxide to give the corresponding N-heteroaromatics has been developed. Several classes of N-heterocycles such as pyridine, quinoline, isoquinoline, and phenanthridine are tolerated. The electrochemical reactions proceed efficiently in aqueous solution without the need for transition-metal catalysts and waste-generating reducing reagents.
- Xu, H.-C.,Xu, P.
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- Mild Deoxygenation of Sulfoxides over Plasmonic Molybdenum Oxide Hybrid with Dramatic Activity Enhancement under Visible Light
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Harvesting solar light to boost commercially important organic synthesis still remains a challenge. Coupling of conventional noble metal catalysts with plasmonic oxide materials which exhibit intense plasmon absorption in the visible light region is a promising option for efficient solar energy utilization in catalysis. Herein, we for the first time demonstrate that plasmonic hydrogen molybdenum bronze coupled with Pt nanoparticles (Pt/HxMoO3-y) shows a high catalytic performance in the deoxygenation of sulfoxides with 1 atm of H2 at room temperature, with dramatic activity enhancement under visible light irradiation relative to dark conditions. The plasmonic molybdenum oxide hybrids with strong plasmon resonance peaks pinning at around 556 nm are obtained via a facile H-spillover process. Pt/HxMoO3-y hybrid provides excellent selectivity for the deoxygenation of various sulfoxides as well as pyridine N-oxides, in which drastically improved catalytic efficiencies are obtained under the irradiation of visible light. Comprehensive analyses reveal that oxygen vacancies massively introduced via a H-spillover process are the main active sites, and the reversible redox property of Mo atoms and strong plasmonic absorption play key roles in this reaction. The catalytic system works under extremely mild conditions and can boost the reaction by the assistance of visible light, offering an ultimately greener protocol to produce sulfides from sulfoxides. Our findings may open up a new strategy for designing plasmon-based catalytic systems that can harness visible light efficiently.
- Kuwahara, Yasutaka,Yoshimura, Yukihiro,Haematsu, Kohei,Yamashita, Hiromi
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- Oxidative ammonolysis of 2,4,6-collidine at vanadium-titanium oxide catalyst
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4-Cyanopyridine was synthesized from the readily obtainable 2,4,6-collidine by oxidative ammonolysis in the presence of vanadium-titanium oxide catalyst. Conditions under which the yield of the product amounted to 73% on the amount of the trimethylpyridin
- Kagarlitsky,Krichevsky
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- A mild and selective deoxygenation of N-oxides with ammonium formate as a catalytic hydrogen transfer agent
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Ammonium formate catalytic transfer hydrogenation in the presence of raney nickel has shown utility for mild and selective deoxygenation of heteroaromatic N-oxides in neutral medium.
- Balicki, Roman,Maciejewski, Grzegorz
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- Photocatalytic deoxygenation of N-O bonds with rhenium complexes: From the reduction of nitrous oxide to pyridineN-oxides
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The accumulation of nitrogen oxides in the environment calls for new pathways to interconvert the various oxidation states of nitrogen, and especially their reduction. However, the large spectrum of reduction potentials covered by nitrogen oxides makes it difficult to find general systems capable of efficiently reducing variousN-oxides. Here, photocatalysis unlocks high energy species able both to circumvent the inherent low reactivity of the greenhouse gas and oxidant N2O (E0(N2O/N2) = +1.77 Vvs.SHE), and to reduce pyridineN-oxides (E1/2(pyridineN-oxide/pyridine) = ?1.04 Vvs.SHE). The rhenium complex [Re(4,4′-tBu-bpy)(CO)3Cl] proved to be efficient in performing both reactions under ambient conditions, enabling the deoxygenation of N2O as well as synthetically relevant and functionalized pyridineN-oxides.
- Anthore-Dalion, Lucile,Cantat, Thibault,Kjellberg, Marianne,Nicolas, Emmanuel,Ohleier, Alexia,Thuéry, Pierre
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- Seeking the Ideal Dehydrating Reagent
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A set of "phosphonium anhydride"reagents is shown to have virtually ideal properties as selective oxygen extractors for net dehydration reactions in a series of illustrative examples.
- Hendrickson, James B.,Hussoin, Md. Sajjat
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- Oxidative ammonolysis of 3(4)-methyl- and 3,4-dimethylpyridines using vanadium oxide catalysts
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Oxidative ammonolysis of 3(4)-methyl- and 3,4-dimethylpyridines using vanadium oxide catalyst doped with Cr2O3, SnO2, and ZrO2 was studied. The yields of nitriles and conversion of the starting compounds were found to depend on the CH-acidity of the latter in the gas phase. The possible mechanisms of the formation of pyridine-3,4-dicarboxylic acid imide at the oxidative ammonolysis of 3,4-dimethylpyridine was discussed. The relation between the activity of the modified catalysts and the proton affinity of the vanadyl oxygen calculated by the extended Hueckel method was established.
- Vorobyev,Serebryanskaya
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- Indium-mediated deoxygenation of amine-N-oxides in aqueous media
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Several aromatic and aliphatic amine-N-oxides were deoxygenated to the corresponding amines in good to quantitative yield using indium metal in neutral aqueous media. Other functional groups such as alkenes, halides, esters, ethers, nitriles, amides and sulfones are unaffected under the present reaction conditions. (C) 2000 Elsevier Science Ltd.
- Yadav,Subba Reddy,Reddy, M. Muralidhar
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- Metal-Free Deoxygenation of Amine N-Oxides: Synthetic and Mechanistic Studies
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We report herein an unprecedented combination of light and P(III)/P(V) redox cycling for the efficient deoxygenation of aromatic amine N-oxides. Moreover, we discovered that a large variety of aliphatic amine N-oxides can easily be deoxygenated by using only phenylsilane. These practically simple approaches proceed well under metal-free conditions, tolerate many functionalities and are highly chemoselective. Combined experimental and computational studies enabled a deep understanding of factors controlling the reactivity of both aromatic and aliphatic amine N-oxides.
- Lecroq, William,Schleinitz, Jules,Billoue, Mallaury,Perfetto, Anna,Gaumont, Annie-Claude,Lalevée, Jacques,Ciofini, Ilaria,Grimaud, Laurence,Lakhdar, Sami
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p. 1237 - 1242
(2021/06/01)
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- Clean protocol for deoxygenation of epoxides to alkenes: Via catalytic hydrogenation using gold
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The epoxidation of olefin as a strategy to protect carbon-carbon double bonds is a well-known procedure in organic synthesis, however the reverse reaction, deprotection/deoxygenation of epoxides is much less developed, despite its potential utility for the synthesis of substituted olefins. Here, we disclose a clean protocol for the selective deprotection of epoxides, by combining commercially available organophosphorus ligands and gold nanoparticles (Au NP). Besides being successfully applied in the deoxygenation of epoxides, the discovered catalytic system also enables the selective reduction N-oxides and sulfoxides using molecular hydrogen as reductant. The Au NP catalyst combined with triethylphosphite P(OEt)3 is remarkably more reactive than solely Au NPs. The method is not only a complementary Au-catalyzed reductive reaction under mild conditions, but also an effective procedure for selective reductions of a wide range of valuable molecules that would be either synthetically inconvenient or even difficult to access by alternative synthetic protocols or by using classical transition metal catalysts. This journal is
- Fiorio, Jhonatan L.,Rossi, Liane M.
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p. 312 - 318
(2021/01/29)
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- Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
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A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
- Bera, Jitendra K.,Pandey, Pragati
-
supporting information
p. 9204 - 9207
(2021/09/20)
-
- Revisiting the synthesis of aryl nitriles: a pivotal role of CAN
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Facilitated by the dual role of Ceric Ammonium Nitrate (CAN), herein we report a cost-effective approach for the cyanation of aryl iodides/bromides with CAN-DMF as an addition to the existing pool of combined cyanation sources. In addition to being an oxidant, CAN acts as a source of nitrogen in our protocol. The reaction is catalyzed by a readily available Cu(ii) salt and the ability of CAN to generate ammonia in the reaction medium is utilized to eliminate the additional requirement of a nitrogen source, ligand, additive or toxic reagents. The mechanistic study suggests an evolution of CN?leading to the synthesis of a variety of aryl nitriles in moderate to good yields. The proposed mechanism is supported by a series of control reactions and labeling experiments.
- Saikia, Rakhee,Park, Kwihwan,Masuda, Hayato,Itoh, Miki,Yamada, Tsuyoshi,Sajiki, Hironao,Mahanta, Sanjeev P.,Thakur, Ashim J.
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p. 1344 - 1351
(2021/02/27)
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- Lewis Acidic Boranes, Lewis Bases, and Equilibrium Constants: A Reliable Scaffold for a Quantitative Lewis Acidity/Basicity Scale
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A quantitative Lewis acidity/basicity scale toward boron-centered Lewis acids has been developed based on a set of 90 experimental equilibrium constants for the reactions of triarylboranes with various O-, N-, S-, and P-centered Lewis bases in dichloromethane at 20 °C. Analysis with the linear free energy relationship log KB=LAB+LBB allows equilibrium constants, KB, to be calculated for any type of borane/Lewis base combination through the sum of two descriptors, one for Lewis acidity (LAB) and one for Lewis basicity (LBB). The resulting Lewis acidity/basicity scale is independent of fixed reference acids/bases and valid for various types of trivalent boron-centered Lewis acids. It is demonstrated that the newly developed Lewis acidity/basicity scale is easily extendable through linear relationships with quantum-chemically calculated or common physical–organic descriptors and known thermodynamic data (ΔH (Formula presented.)). Furthermore, this experimental platform can be utilized for the rational development of borane-catalyzed reactions.
- Mayer, Robert J.,Hampel, Nathalie,Ofial, Armin R.
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supporting information
p. 4070 - 4080
(2021/01/29)
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- Method for continuous preparation of nitriles in a pipelined reactor (by machine translation)
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The method comprises the following steps that a tin catalyst is coated on the inner wall of the pipeline reactor; and the method comprises the following steps: coating a tin catalyst on the inner wall of the pipeline reactor. The amide solution and the catalytic auxiliary agent are mixed and then sent to a pipeline reactor, and the amide is dehydrated to generate nitrile at the reaction pressure of 0.1 - 2.0 mpa and 100 - 200 °C reaction temperature. The resulting reaction product was separated to give the crude product of the nitrile to which the amide corresponded. In the pipeline reactor, the corresponding nitrile is continuously prepared under the action of the tin catalyst, a dehydrating agent is not needed, byproducts only are water, and three wastes are reduced. (by machine translation)
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-
Paragraph 0036-0047; 0056; 0058
(2020/12/14)
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- Method for catalyzing receptor-free dehydrogenation of primary amine to generate nitrile by Ru coordination compound
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The invention discloses a method for catalyzing receptor-free dehydrogenation of primary amine to generate nitrile by a Ru coordination compound. The method comprises: adding a Ru coordination compound, an alkali, a primary amine and an organic solvent into a reaction test tube according to a mol ratio of 1:100:(100-500):1000-3000, and carrying out a stirring reaction under the condition of 80 to120 DEG C; and when gas chromatography monitors that the raw materials completely disappear, stopping the reaction, collecting the reaction solution, centrifuging the reaction solution, taking the supernatant, extracting with dichloromethane, merging the organic phases, drying, filtering, evaporating the organic solvent under reduced pressure to obtain a filtrate, and carrying out column chromatography purification on the filtrate to obtain the target product nitrile. According to the invention, the catalyst is good in activity, single in catalytic system, good in product selectivity, simple in subsequent treatment and good in system universality after the reaction is finished, has a good catalytic effect on various aryl, alkyl and heteroaryl substituted primary amines, and also has a gooddehydrogenation performance on secondary amines.
- -
-
Paragraph 0034-0039; 0220-0225
(2020/09/16)
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- Metal-free, redox-neutral, site-selective access to heteroarylamine via direct radical?radical cross-coupling powered by visible light photocatalysis
-
Transition-metal-catalyzed C?N bond-forming reactions have emerged as fundamental and powerful tools to construct arylamines, a common structure found in drug agents, natural products, and fine chemicals. Reported herein is an alternative access to heteroarylamine via radical?radical cross-coupling pathway, powered by visible light catalysis without any aid of external oxidant and reductant. Only by visible light irradiation of a photocatalyst, such as a metal-free photocatalyst, does the cascade single-electron transfer event for amines and heteroaryl nitriles occur, demonstrated by steady-state and transient spectroscopic studies, resulting in an amine radical cation and aryl radical anion in situ for C?N bond formation. The metal-free and redox economic nature, high efficiency, and site-selectivity of C?N cross-coupling of a range of available amines, hydroxylamines, and hydrazines with heteroaryl nitriles make this protocol promising in both academic and industrial settings.
- Zhou, Chao,Lei, Tao,Wei, Xiang-Zhu,Ye, Chen,Liu, Zan,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
-
supporting information
p. 16805 - 16813
(2020/11/09)
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- Acceptorless dehydrogenation of amines to nitriles catalyzed by N-heterocyclic carbene-nitrogen-phosphine chelated bimetallic ruthenium (II) complex
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We have developed a clean, atom-economical and environmentally friendly route for acceptorless dehydrogenation of amines to nitriles by combining a new dual N-heterocyclic carbene-nitrogen-phosphine ligand R(CNP)2 (R = o-xylyl) with a ruthenium precursor [RuCl2(η6-C6H6)]2. In this system, the electronic and steric factors of amines had a negligible influence on the reaction and a broad range of functional groups were well tolerated. All of the investigated amines could be converted to nitriles in good yield of up to 99% with excellent selectivity. The unprecedented catalytic performance of this system is attributed to the synergistic effect of two ruthenium centers chelated by R(CNP)2 and a plausible reaction mechanism is proposed according to the active species found via in situ NMR and HRMS.
- Chen, Hua,Fu, Haiyan,Ji, Li,Li, Ruixiang,Nie, Xufeng,Zheng, Yanling
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p. 378 - 385
(2020/10/02)
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- Method for continuous preparation of nitriles by amides (by machine translation)
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The method comprises the following steps: preparing a lead salt supported by a molecular sieve by a lead salt and a molecular sieve through an impregnation method; and filling a molecular sieve-loaded lead catalyst into a fixed bed reactor. The amide or amide solution is sent into a fixed bed reactor from the top of the fixed bed to be subjected to catalytic dehydration, and the obtained reaction product is led out from the bottom of the fixed bed. The reaction product is separated to obtain the crude product of the nitrile corresponding to the amide. A fixed bed continuous production process is adopted, the reaction process is simple, the production efficiency is high, the product post-treatment is simple, and industrial production is easy to realize. (by machine translation)
- -
-
Paragraph 0033-0054; 0061-0066
(2020/12/15)
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- Synthesis of nitriles via the iodine-mediated dehydrosulfurization of thioamides
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A simple general method for the synthesis of nitriles using the inexpensive and easy to handle iodine (I2) is described herein. The reaction of thioamides with I2 in the presence of triethylamine at room temperature under aerobic conditions afforded various nitriles bearing aryl, vinyl, and alkyl groups in good-to-excellent yields. This method was also effective for conversion from thioureas to cyanamides.
- Murata, Yuki,Iwasa, Hitomi,Matsumura, Mio,Yasuike, Shuji
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p. 679 - 681
(2020/07/30)
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- Metal-free dehydrosulfurization of thioamides to nitriles under visible light
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A visible light-mediated, metal-free dehydrosulfurization reaction of thioamides to nitriles is described. This reaction features high yields, mild reaction conditions, and the use of a cheap organic dye as the photoredox catalyst and air as the oxidant.
- Xu, Tianxiao,Cao, Tianpeng,Feng, Qingyuan,Huang, Shenlin,Liao, Saihu
-
supporting information
p. 5151 - 5153
(2020/05/26)
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- Ionic-Liquid Controlled Nitration of Double Bond: Highly Selective Synthesis of Nitrostyrenes and Benzonitriles
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Unprecedented in literature, the conversion of aryl alkenes into β-nitrostyrenes (2) or benzonitriles (3) with sodium nitrite can be governed by an appropriate choice of ionic liquid (IL) medium. A general trend was found for the selectivity of these processes, which depends on the nature of IL, with imidazolium-based ILs, such as [Bmim]Cl, that favor the C–H nitration leading to β-nitrostyrenes, while tetraalkylammonium-based ILs, such as TBAA, privilege the C=C bond cleavage affording benzonitriles. Besides a substrate scope, mechanistic hypotheses were provided on the origin of the different selectivity in the two kinds of ILs, based on their own tunable properties such as polarity, viscosity, and solvent cage effects.
- Casiello, Michele,Caputo, Daniela,Fusco, Caterina,Cotugno, Pietro,Rizzi, Vito,Dell'Anna, Maria Michela,D'Accolti, Lucia,Nacci, Angelo
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supporting information
p. 6012 - 6018
(2020/08/24)
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- Photocatalytic Conversion of Benzyl Alcohols/Methyl Arenes to Aryl Nitriles via H-Abstraction by Azide Radical
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This report presents the visible-light-assisted synthesis of aryl nitriles from easily accessible alcohols or methyl arenes in the presence of O2. Organic photoredox catalyst, 4CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene), induces single electron transfer (SET) from azide N3? and generates azide radical N3?.The photogenerated N3? abstracts H atom from α-C?H bond of benzylic system, which provides aldehyde and hydrazoic acid (HN3) in situ. This reaction subsequently forms azido alcohol intermediate that transforms into nitrile with the assistance of triflic acid (Br?nsted acid). A range of alcohols and methyl arenes successfully underwent cyanation at room temperature with good to excellent yields and showed good functional group tolerance.
- Shee, Maniklal,Shah, Sk. Sheriff,Singh, N. D. Pradeep
-
supporting information
p. 14070 - 14074
(2020/10/12)
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- Organophotoredox assisted cyanation of bromoarenes: via silyl-radical-mediated bromine abstraction
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The insertion of a nitrile (-CN) group into arenes through the direct functionalization of the C(sp2)-Br bond is a challenging reaction. Herein, we report an organophotoredox method for the cyanation of aryl bromides using the organic photoredox catalyst 4CzIPN and tosyl cyanide (TsCN) as the nitrile source. A photogenerated silyl radical, via a single electron transfer (SET) mechanism, was employed to abstract bromine from aryl bromide to provide an aryl radical, which was concomitantly intercepted by TsCN to afford the aromatic nitrile. A range of substrates containing electron-donating and -withdrawing groups was demonstrated to undergo cyanation at room temperature in good yields.
- Shah, Sk. Sheriff,Shee, Maniklal,Singh, N. D. Pradeep
-
supporting information
p. 4240 - 4243
(2020/04/22)
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- Method for preparing aryl primary amide by adopting metal-catalyzed one-pot method
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The invention discloses a method for synthesizing aryl primary amide by adopting a metal-catalyzed one-pot method. The method comprises the steps of: taking aryl bromidess as raw materials, allowing the aryl bromidess to react with a cyanide source under the action of a palladium catalyst, substituting bromine on an aromatic ring with cyano to obtain cyano aromatic hydrocarbon, directly adding anaqueous solution of alkali into the reaction solution without aftertreatment, and carrying out hydrolysis reaction to obtain aryl primary amide. Compared with the prior art, the method for preparing aryl primary amide from the aryl bromides has the advantages of the short synthesis route, fewer reaction steps, simple operation, mild conditions, the high conversion rate, low toxicity and industrialproduction potential.
- -
-
Paragraph 0031; 0032
(2020/04/06)
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- Catalytic oxidative conversion of aldehydes into nitriles using NH3·H2O/FeCl2/NaI/Na2S2O8: A practical approach to febuxostat
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A novel approach to convert aldehydes into nitriles using NH3·H2O/FeCl2/NaI/Na2S2O8 has been developed. Both alkyl and aryl nitriles were obtained in good to excellent yields. Electron-withdrawing and electron-donating groups, such as fluoro, chloro, bromo, nitro, ester, cyano, trifluoromethyl and alkoxy were tolerated. Notably, febuxostat and its intermediate, ethyl 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylate, were obtained in excellent yields.
- Chen, Han,Sun, Sijia,Xi, Haoying,Hu, Kaifang,Zhang, Ning,Qu, Jingping,Zhou, Yuhan
-
supporting information
p. 1434 - 1436
(2019/05/01)
-
- Triphenylbismuth Dichloride-Mediated Conversion of Thioamides to Nitriles
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Thioamides were efficiently converted to nitriles using the pentavalent triphenylbismuth dichloride in combination with triethylamine. The reaction involved the dehydrosulfurization of primary thioamides to afford substituted aromatic or aliphatic nitriles in good to excellent yields. The process was also successfully extended to the synthesis of cyanamides starting from the corresponding thioureas and of thiocyanates from dithiocarbamates.
- Gopi, Elumalai,Gravel, Edmond,Doris, Eric
-
supporting information
p. 4043 - 4045
(2019/06/24)
-
- Catalytic Dehydrosulfurization of Thioamides to Nitriles by Gold Nanoparticles Supported on Carbon Nanotubes
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A gold-carbon nanotube nanohybrid was shown to act as an efficient heterogeneous catalyst in the smooth and selective conversion of thioamides to the corresponding nitriles. The reaction was performed under mild conditions (room temperature, atmospheric pressure of oxygen) using only a gold loading of 0.35 mol %. Substituted aromatic or aliphatic nitriles were produced in very good to excellent yields and the catalyst could be easily recycled and reused over several consecutive cycles with no loss in dehydrosulfurization performances.
- Gopi, Elumalai,Geertsen, Valérie,Gravel, Edmond,Doris, Eric
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p. 5758 - 5761
(2019/05/21)
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- Synthesis, characterization and catalytic performance of Pd(II) complex immobilized on Fe3O4@SiO2 nanoparticles for the ligand-free cyanation of aryl halides using K4Fe(CN)6
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This work shows the preparation of a novel magnetic catalyst via immobilization of Pd(II)-N-benzyl-N-(4-bromophenyl)-5-amino-1H-tetrazole complex on the Fe3O4@SiO2 nanoparticles (NPs). The application of Fe3O4@SiO2 NPs supported Pd(II)-N-benzyl-N-(4-bromophenyl)-5-amino-1H-tetrazole complex [Fe3O4@SiO2-BAT-Pd(II)] nanocatalyst is described for the cyanation of aryl iodides and bromides to the corresponding aryl nitriles using potassium hexacyanoferrate(II) [K4Fe(CN)6] as a non-toxic and economic cyanating agent under ligand- and additive-free conditions. Some aryl nitriles were efficiently synthesized from the corresponding aryl bromides and iodides in the presence of Fe3O4@SiO2-BAT-Pd(II) nanocomplex. The core-shell nanocomplex demonstrated the superior catalytic performance for the synthesis of synthetically valuable aryl nitriles within good to excellent yields. This process eliminates the need to handle highly toxic metal cyanides, and it can be easily recovered and reused for six consecutive runs with no decreasing of its catalytic capability. Highlights: Preparation of Pd(II) complex immobilized on Fe3O4@SiO2 nanoparticles [Fe3O4@SiO2-BAT-Pd(II) nanocomplex]. Characterization of Fe3O4@SiO2-BAT-Pd(II) nanocomplex using XRD, FT-IR, EDS, VSM, TEM and FESEM analyses. Catalytic cyanation of the various aryl halides with K4Fe(CN)6 under ligand-free conditions. The nanocomplex can be recovered and isolated six times with no significant loss of its catalytic ability.
- Nasrollahzadeh, Mahmoud,Maryami, Mahboobe,Sajjadi, Mohaddeseh,Mehdipour, Ebrahim
-
-
- Efficient cyanation of aryl halides with K4[Fe(CN)6] catalyzed by encapsulated palladium nanoparticles in biguanidine–chitosan matrix as core–shell recyclable heterogeneous nanocatalyst
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Palladium nanoparticles encapsulated in biguanidine–functionalized chitosan matrix (Pd@CS–biguanidine) was applied as a reusable and core–shell nanocatalyst for cyanation of aryl iodides and bromides with K4[Fe(CN)6] as the cyanating agent. The nitriles were generated in good to excellent yield and the catalyst can be recycled and reapplied up to seven times with no significant change in its catalytic performance.
- Veisi, Hojat
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p. 212 - 216
(2019/01/03)
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- Biosynthesis of Pd/MnO2 nanocomposite using Solanum melongena plant extract and its application for the one-pot synthesis of 5-substituted 1H-tetrazoles from aryl halides
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In this work, for the first time, Solanum melongena plant extract was used for the green synthesis of Pd/MnO2 nanocomposite via reduction osf Pd(II) ions to Pd(0) and their immobilization on the surface of manganese dioxide (MnO2) nanoparticles (NPs) as an effective support. The synthesized nanocomposite were characterized by various analytical techniques such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS) and UV–Vis spectroscopy. The catalytic activity of Pd/MnO2 nanocomposite was used as a heterogeneous catalyst for the one-pot synthesis of 5-substituted 1H-tetrazoles from aryl halides containing various electron-donating or electron-withdrawing groups in the presence of K4[Fe (CN)6] as non-toxic cyanide source and sodium azide. The products were obtained in good yields via a simple methodology and easy work-up. The nanocatalyst can be recycled and reused several times with no remarkable loss of activity.
- Nasrollahzadeh, Mahmoud,Ghorbannezhad, Fatemeh,Sajadi, S. Mohammad
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-
- Corresponding amine nitrile and method of manufacturing thereof
-
The invention relates to a manufacturing method of nitrile. Compared with the prior art, the manufacturing method has the characteristics of significantly reduced using amount of an ammonia source, low environmental pressure, low energy consumption, low production cost, high purity and yield of a nitrile product and the like, and nitrile with a more complex structure can be obtained. The invention also relates to a method for manufacturing corresponding amine from nitrile.
- -
-
Paragraph 0150; 0151; 0152; 0154
(2018/05/07)
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- Nickel-catalyzed cyanation of phenol derivatives activated by 2,4,6-trichloro-1,3,5-triazine
-
A nickel-catalyzed cyanation of phenol derivatives activated by 2,4,6-trichloro-1,3,5-triazine (TCT) using aminoacetonitrile as the cyanating agent is described. This catalytic system delivered the desired products in moderate to good yields with good substrate compatibility. The readily available starting materials, cost-effective nickel catalyst and metal-free cyanating agent are the major features of the present method.
- Wang, Liang,Wang, Yaoyao,Shen, Jun,Chen, Qun,He, Ming-Yang
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supporting information
p. 4816 - 4820
(2018/07/13)
-
- Cu(OAc)2/malononitrile/water: A simple reaction system for synthesis of aromatic nitriles from aldoximes
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A simple method for the preparation of nitriles in moderate to good yield has been achieved by treatment of aromatic and heterocyclic aldoximes with malononitrile in water at reflux in the presence of copper acetate as catalyst. Arylaldoximes with an electron-donating group showed the highest reactivity, their conversion being achievable at room temperature.
- Ma, Xiaoyun,He, Daqin,Chen, Zhengjian
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p. 595 - 597
(2018/12/13)
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- Catalytic Promiscuity of Galactose Oxidase: A Mild Synthesis of Nitriles from Alcohols, Air, and Ammonia
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We report an unprecedented catalytically promiscuous activity of the copper-dependent enzyme galactose oxidase. The enzyme catalyses the one-pot conversion of alcohols into the related nitriles under mild reaction conditions in ammonium buffer, consuming ammonia as the source of nitrogen and dioxygen (from air at atmospheric pressure) as the only oxidant. Thus, this green method does not require either cyanide salts, toxic metals, or undesired oxidants in stoichiometric amounts. The substrate scope of the reaction includes benzyl and cinnamyl alcohols as well as 4- and 3-pyridylmethanol, giving access to valuable chemical compounds. The oxidation proceeds through oxidation from alcohol to aldehyde, in situ imine formation, and final direct oxidation to nitrile.
- Vilím, Jan,Knaus, Tanja,Mutti, Francesco G.
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supporting information
p. 14240 - 14244
(2018/10/15)
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- Intramolecular alkene hydroamination and degradation of amidines: Divergent behavior of rare earth metal amidinate intermediates
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Direct N-H addition of amidines to alkenes is a highly valuable but challenging transformation that remains elusive. Now, the intramolecular hydroamidination of N-alkenylamidines is achieved by using a rare earth catalyst, which provides an efficient and atom-economical approach for substituted imidazolines and tetrahydropyrimidines. Moreover, a mild and efficient method for the catalytic degradation of amidines to give amines and nitriles is also developed. Additionally, amidine reconstruction followed by an intramolecular alkene hydroamidination strategy for the synthesis of substituted imidazolines and tetrahydropyrimidines from secondary enamines and inactive amidines has also been established, which may circumvent the need for some unavailable starting materials. The mechanistic studies prove that these reactions proceed via a key lanthanide amidinate intermediate that can undergo substrate- and amine-controlled chemodivergent transformations: intramolecular alkene insertion, nitrile extrusion, amidinate reconstruction, or a combination of the reactions. The results presented here not only demonstrate the synthetic potential and versatility of alkene hydroamidination with substrates, but also provide a good insight into the factors that promote or deter the hydroamidination of alkenes.
- Zhang, Dexing,Liu, Ruiting,Zhou, Xigeng
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p. 5573 - 5581
(2018/11/20)
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- In situ immobilized palladium nanoparticles on surface of poly-methyldopa coated-magnetic nanoparticles (Fe3O4@PMDA/Pd): A magnetically recyclable nanocatalyst for cyanation of aryl halides with K4[Fe(CN)6]
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Poly-methyldopa (PMDP)-coated Fe3O4 nanoparticles (Fe3O4@PMDP) have been synthesized through a simple and green procedure. In the present study, for the first time, Pd nanoparticles were successfully deposited using Fe3O4@PMDP as a core-shell magnetic coordinator and stabilizer agent. In this protocol, Pd ions were adsorbed on surfaces of Fe3O4@PMDP through immersion of the PMDP-coated Fe3O4 nanoparticles into a palladium plating bath. Next, they were reduced in situ to palladium nanoparticles using PMDP's N-containing groups and reducing ability. The structure, morphology and physicochemical properties of the synthesized nanoparticles were characterized by different analytical techniques such as energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscope (FESEM), Fourier-transform infrared spectroscopy (FT-IR) spectroscopy, high resolution transmission electron microscopy (HR-TEM), inductively coupled plasma (ICP), thermo gravimetric analysis (TGA), vibrating sample magnetometer (VSM), and X-ray photoelectron spectroscopy (XPS). Core-shell Fe3O4@PMDP/Pd(0) nanoparticles showed excellent catalytic performance as a reusable nanocatalyst for cyanation of aryl iodides and bromides with K4[Fe(CN)6] as the cyanating agent. The nitriles were obtained in good to excellent yield and the catalyst can be recycled and reapplied up to seven times with only very slight decrease in its catalytic performance.
- Veisi, Hojat,Hemmati, Saba,Safarimehr, Parisa
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p. 204 - 212
(2018/07/25)
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- One-pot conversion of aldehydes to nitriles mediated by TiCl4
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A simple and convenient one-pot synthesis of nitriles from the corresponding aliphatic and aromatic aldehydes has been developed. The titanium tetrachloride assisted reaction was conducted in pyridine under mild conditions using various types of aldehyde precursors and gave the corresponding nitriles in excellent yields. The application of the adopted protocol to isolated aldoxime intermediates provided the corresponding nitriles with yields comparable to those using the one-pot procedure.
- Leggio, Antonella,Belsito, Emilia Lucia,Gallo, Sonia,Liguori, Angelo
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supporting information
p. 1512 - 1514
(2017/03/23)
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- Copper (II)-catalysed direct conversion of aldehydes into nitriles in acetonitrile
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A mild one-pot method for the direct conversion of aryl, heteroaryl and alkyl aldehydes into nitriles was achieved by forming the corresponding oximes in situ with NH2OH and allowing them to react with CuO and acetonitrile. Yields of the 13 nitriles prepared were moderate to very good (62–91%).
- Ma, Xiaoyun,Ao, Jun,Chen, Zhengjian,Liu, Yi
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p. 465 - 468
(2017/08/18)
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- Trinuclear complexes of palladium(II) with chalcogenated N-heterocyclic carbenes: Catalysis of selective nitrile-primary amide interconversion and Sonogashira coupling
-
3-Methyl-1-(2-(phenylthio/seleno)ethyl)-1H-benzo[d]imidazol-3-ium iodide (L1/L2), a precursor of sulfated/selenated N-heterocyclic carbene, was synthesized by the reaction of benzimidazole with 1,2-dichloroethane followed by treatment with PhS/SeNa and MeI. The reaction of L1/L2 with Ag2O followed by treatment with [Pd(CH3CN)2Cl2] (metal to ligand ratio 3:2), i.e. transmetallation, resulted in trinuclear palladium(ii) complexes [Pd3(L1/L2-HI)2(CH3CN)Cl6] (1-2). The complexes were characterized with 1H, 13C{1H} and 77Se{1H} NMR (2 only), elemental analyses, HR-MS and single-crystal X-ray diffraction. The geometry of three Pd atoms in each complex is nearly square planar. The Pd-S/Se, Pd-C, Pd-N and Pd-Cl bond distances (?) in 1/2 are 2.3179(19)/2.4312(10), 1.968(7)/1.952(4), 2.073(8)/2.079(4) and 2.2784(19)-2.298(2)/2.292(2)-2.3003(15), respectively. In both the complexes, all Cl are trans to each other. For the central Pd atom, two benzimidazole rings are also trans to each other. The C-H?Cl non-covalent interactions result in a three-dimensional network. The moisture and air insensitive trinuclear Pd(ii) complexes 1 and 2 are thermally stable and efficient as a catalyst for nitrile-amide interconversion and amine-free Sonogashira C-C coupling (in the presence of CuI). The optimum temperature is 80 °C for the interconversion and 110 °C for the coupling. The catalytic protocols are applicable to both aliphatic and aromatic amides/nitriles. The optimum catalyst loading is 1 mol% for the C-C coupling and 0.5 to 1 mol% for the interconversion. K2CO3 as a base gives the best result for Sonogashira C-C coupling. In the conversion of nitriles to amides, the formation of an acid was not detected. After using once, 1/2 can carry out the conversion of ten fresh lots of nitriles to amides with almost the same efficiency. The real catalytic species for the interconversion and coupling appear to be based on Pd(ii) and Pd(0), respectively.
- Dubey, Pooja,Gupta, Sonu,Singh, Ajai K.
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p. 13065 - 13076
(2017/10/13)
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- Visible-light-responsive catalysis of a zinc-introduced lacunary disilicoicosatungstate for the deoxygenation of pyridine N-oxides
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We herein report the synthesis and photoredox catalysis of a mononuclear zinc-introduced lacunary disilicoicosatungstate TBA7[{Zn(CH3CN)}(γ-SiW10O34){γ-SiW10O32(CH3CONH)}(μ-O)2] (II, TBA = tetra-n-butylammonium). POM II showed efficient photocatalytic activity in the selective deoxygenation of pyridine N-oxides under visible light irradiation (λ > 400 nm).
- Jeong, Jinu,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
-
supporting information
p. 13226 - 13229
(2017/11/27)
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- Platinum-supporting hollandite-type vanadium-chromium mixed oxides as efficient heterogeneous catalysts for deoxygenation of sulfoxides under atmospheric H2 pressure
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Deoxygenation of sulfoxides to their corresponding sulfides is an important reaction, and the development of efficient heterogeneous catalysts that can utilize molecular hydrogen (H2) as a reducing agent is highly desired. In this study, we successfully developed a new concept in heterogeneous catalysts, platinum-supporting hollandite-type vanadium-chromium mixed oxide catalysts (Pt/V(1-x)Crx-Hol, x: Cr/(V + Cr) molar ratio of the precursor solution), for sulfoxide deoxygenation with H2. Hollandite-type vanadium-chromium mixed oxides (V(1-x)Crx-Hol) that did not support platinum could stoichiometrically deoxygenate methyl phenyl sulfoxide to methyl phenyl sulfide, and the V3+ species in V(1-x)Crx-Hol were oxidized to V4+ after deoxygenation. However, the V4+ species could not be re-reduced with H2. By supporting platinum nanoparticles on V(1-x)Crx-Hol, the re-reduction of the oxidized vanadium species with H2 became possible. Thus, in the presence of Pt/V(1-x)Crx-Hol, catalytic sulfoxide deoxygenation with H2 as the reducing agent can be realized; the deoxygenation occurs on V(1-x)Crx-Hol, and the role of platinum is to re-reduce the oxidized vanadium species with H2. In the presence of Pt/V0.7Cr0.3-Hol, various types of structurally diverse sulfoxides could be selectively converted into their corresponding sulfides under atmospheric H2 pressure (1 atm). In addition, the present system was applicable to the deoxygenation of pyridine N-oxides to their corresponding pyridines. The observed catalysis was truly heterogeneous, and the Pt/V0.7Cr0.3-Hol catalyst could be reused for sulfoxide deoxygenation, although the performance was reduced.
- Uematsu, Tsubasa,Ogasawara, Yoshiyuki,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
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p. 1912 - 1920
(2017/07/15)
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- A Bifunctional Reagent Designed for the Mild, Nucleophilic Functionalization of Pyridines
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Herein is reported the design and application of a reagent for the direct functionalization of pyridines. These reactions occur under mild conditions and exhibit broad functional group tolerance, enabling the late-stage functionalization of drug-like molecules. The reagent can be easily prepared on large scale from inexpensive reagents, and reacts in the title reaction with acetonitrile, sodium chloride, and sodium methanesulfonate as the sole byproducts. Although this Communication focuses primarily on reactions with cyanide as nucleophile, preliminary experiments with other nucleophiles foreshadow the broad reaching synthetic utility of this approach.
- Fier, Patrick S.
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p. 9499 - 9502
(2017/07/24)
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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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- Direct synthesis of nitriles by Cu/DMEDA/TEMPO-catalyzed aerobic oxidation of primary amines with air
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By screening the copper catalysts, ligands, and the reaction conditions, a simple CuCl/DMEDA/TEMPO catalyst system readily available from commercial sources is developed for a direct and selective synthesis of the useful nitriles by an aerobic oxidation reaction of primary amines using air as an advantageous oxidant under mild conditions.
- Ma, Xian-Tao,Xu, Hao,Xiao, Ying-Lin,Su, Chen-Liang,Liu, Jian-Ping,Xu, Qing
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p. 1336 - 1339
(2017/06/21)
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- Synthesis of nitriles from aldehydes with trimethylphenylammonium tribromide and ammonium acetate
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Various aromatic and heterocyclic aldehydes were easily converted to respective nitriles with the combination of trimethylphenylammonium tribromide and ammonium acetate in good yields at room temperature.
- Sayama, Shinsei
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p. 1796 - 1802
(2016/11/06)
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- Direct synthesis of nitriles from aldehydes with hydroxylamine-O-sulfonic acid in acidic water
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Herein is reported the selective transformation of aldehydes to nitriles in the presence of hydroxylamine-O-sulfonic acid (NH2OSO3H) as a source of the N atom and acidic water. The reaction works with high yields for a large array of aromatic and aliphatic aldehydes, as well as hindered aldehydes and conjugated aldehydes without purification. The reaction conditions are very mild and tolerate a wide array of functional groups. In principle, the reaction can be completed in vinegar.
- Quinn, Dylan J.,Haun, Graham J.,Moura-Letts, Gustavo
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supporting information
p. 3844 - 3847
(2016/08/02)
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- Pd Catalysis in Cyanide-Free Synthesis of Nitriles from Haloarenes via Isoxazolines
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A method to obtain aryl nitriles from the corresponding halides by Pd catalysis, in the absence of any cyanide source, is reported. The reaction of an aryl halide, ethyl nitroacetate, and an olefin readily delivers an aromatic nitrile. A variety of aryl iodides/bromides have been converted into the corresponding cyanoarenes in fair to excellent yields. The reaction likely involves the following steps: (a) Pd-catalyzed α-arylation of ethyl nitroacetate; (b) nitrile oxide formation; (c) [3 + 2]-cycloaddition with an olefin to provide an isoxazoline; (d) isoxazoline cleavage to benzonitrile formation.
- Maestri, Giovanni,Ca?eque, Tatiana,Della Ca, Nicola,Derat, Etienne,Catellani, Marta,Chiusoli, Gian Paolo,Malacria, Max
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supporting information
p. 6108 - 6111
(2016/12/09)
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- Alkali α-MnO2/Na: XMnO2 collaboratively catalyzed ammoxidation-Pinner tandem reaction of aldehydes
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The tandem reaction is a growing field to yield important advances toward green and sustainable chemistry. Herein, we report a bifunctional manganese oxide catalyst with an interface binding redox phase (α-MnO2) and a basic phase (NaxMnO2). The molar ratio of NaOH/Mn plays a great role in the formation of α-MnO2/NaxMnO2. The sodium cation is essential for the formation of a basic NaxMnO2 phase while the potassium cation promotes the formation of a redox-active α-MnO2 phase. The interface structure of α-MnO2/NaxMnO2 geometrically favors the ammoxidation-Pinner tandem reaction to synthesize imidates in a 58-96% yield from aldehydes. Thus a phase collaborative effect is observed. In the ammoxidation process, the redox cycle of MnIV/MnIII is involved and the lattice oxygen in the α-MnO2 phase acts as an active oxygen species. The O-H in methanol is activated and dissociated on the basic sites of NaxMnO2 to the adsorbed methoxyl species to facilitate the Pinner synthesis. This approach bypasses the conventional synthesis of imidates, which suffer from harsh reaction conditions and the requirement for multiple steps.
- Jia, Xiuquan,Ma, Jiping,Wang, Min,Li, Xiaofang,Gao, Jin,Xu, Jie
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p. 7429 - 7436
(2016/10/21)
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