- Product selectivity controlled by manganese oxide crystals in catalytic ammoxidation
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The performances of heterogeneous catalysts can be effectively tuned by changing the catalyst structures. Here we report a controllable nitrile synthesis from alcohol ammoxidation, where the nitrile hydration side reaction could be efficiently prevented by changing the manganese oxide catalysts. α-Mn2O3 based catalysts are highly selective for nitrile synthesis, but MnO2-based catalysts including α, β, γ, and δ phases favour the amide production from tandem ammoxidation and hydration steps. Multiple structural, kinetic, and spectroscopic investigations reveal that water decomposition is hindered on α-Mn2O3, thus to switch off the nitrile hydration. In addition, the selectivity-control feature of manganese oxide catalysts is mainly related to their crystalline nature rather than oxide morphology, although the morphological issue is usually regarded as a crucial factor in many reactions.
- Hui, Yu,Luo, Qingsong,Qin, Yucai,Song, Lijuan,Wang, Hai,Wang, Liang,Xiao, Feng-Shou
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p. 2164 - 2172
(2021/09/20)
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- Direct C(sp3)-H Cyanation Enabled by a Highly Active Decatungstate Photocatalyst
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A highly efficient, direct C(sp3)-H cyanation was developed under mild photocatalytic conditions. The method enabled the direct cyanation of various C(sp3)-H substrates with excellent functional group tolerance. Notably, complex natural products and bioactive compounds were efficiently cyanated.
- Kim, Kunsoon,Lee, Seulchan,Hong, Soon Hyeok
-
supporting information
p. 5501 - 5505
(2021/07/26)
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- Ruthenium(II)-Complex-Catalyzed Acceptorless Double Dehydrogenation of Primary Amines to Nitriles
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Acceptorless dehydrogenative oxidation of primary amines into nitriles using an in situ complex derived from commercially available dichloro(1,5-cyclooctadiene) ruthenium(II) complex and simple hexamethylenetetramine has been demonstrated. The synthetic protocol is highly selective and yields the nitrile compounds in moderate to excellent yields and produces hydrogen as the sole byproduct.
- Kannan, Muthukumar,Muthaiah, Senthilkumar
-
supporting information
p. 1073 - 1076
(2020/07/04)
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- Acceptorless dehydrogenation of amines and alcohols using simple ruthenium chloride
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A highly efficient, economic and environmental friendly catalyst system has been developed for the dehydrogenation of alcohols and amines using simple RuCl3·nH2O and N-benzylhexamethylenetetramine. The in situ catalyst system efficiently oxidized the primary and secondary amines and secondary alcohols into nitrile, imine and ketone products, respectively in moderate to excellent yields. The developed catalyst system was also found to be efficient for the dehydrogenation of N-heterocyles. A detailed mechanism study revealed the first example of N-benzylhexamethylenetetramine (HMTA-Bz) being simultaneously acting as base, reducing agent and hydride source to generate the [Ru(II)(H)2] species as the active catalyst. The mechanism studies also revealed both the alcohol and amine oxidation involves dehydrogenative pathway with the evolution of hydrogen as the only by-product. The developed catalyst system also provides possible platform for the release of hydrogen from liquid organic hydrogen carriers (LOHCs).
- Barteja, Parul,Devi, Preeti,Kannan, Muthukumar,Muthaiah, Senthilkumar
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-
- An Efficient Synthesis of Nitriles from Aldoximes in the Presence of Trifluoromethanesulfonic Anhydride in Mild Conditions
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Abstract: A new and convenient protocol has been proposed for the transformation of aldoximes to nitriles using trifluoromethanesulfonic anhydride and triethylamine. The proposed method allows a range of aldoximes, including aromatic, heterocyclic, aliphatic, and cycloaliphatic aldoximes, to be converted to the corresponding nitriles in good to excellent yields.
- Uludag, N.
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p. 1640 - 1645
(2020/10/22)
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- One-pot synthesis of aldoximes from alkenes: Via Rh-catalysed hydroformylation in an aqueous solvent system
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Aldoxime synthesis directly starting from alkenes was successfully achieved through the combination of hydroformylation and subsequent condensation of the aldehyde intermediate with aqueous hydroxylamine in a one-pot process. The metal complex Rh(acac)(CO)2 and the water-soluble ligand sulfoxantphos were used as the catalyst system, providing high regioselectivities in the initial hydroformylation. A mixture of water and 1-butanol was used as an environmentally benign solvent system, ensuring sufficient contact of the aqueous catalyst phase and the organic substrate phase. The reaction conditions were systematically optimised by Design of Experiments (DoE) using 1-octene as a model substrate. A yield of 85% of the desired linear, terminal aldoxime ((E/Z)-nonanal oxime) at 95% regioselectivity was achieved. Other terminal alkenes were also converted successfully under the optimised conditions to the corresponding linear aldoximes, including renewable substrates. Differences of the reaction rate have been investigated by recording the gas consumption, whereby turnover frequencies (TOFs) >2000 h-1 were observed for 4-vinylcyclohexene and styrene, respectively. The high potential of aldoximes as platform intermediates was shown by their subsequent transformation into the corresponding linear nitriles using aldoxime dehydratases as biocatalysts. The overall reaction sequence thus allows for a straightforward synthesis of linear nitriles from alkenes with water being the only by-product, which formally represents an anti-Markovnikov hydrocyanation of readily available 1-alkenes.
- Gr?ger, H.,Guntermann, A.,Hinzmann, A.,Jolmes, T.,Panke, D.,Plass, C.,R?sler, J.,Seidensticker, T.,Terhorst, M.,Vogt, D.,Vorholt, A. J.
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p. 7974 - 7982
(2020/11/30)
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- Atomically Dispersed Ru on Manganese Oxide Catalyst Boosts Oxidative Cyanation
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There is a strong incentive for environmentally benign and sustainable production of organic nitriles to avoid the use of toxic cyanides. Here we report that manganese oxide nanorod-supported single-site Ru catalysts are active, selective, and stable for oxidative cyanation of various alcohols to give the corresponding nitriles with molecular oxygen and ammonia as the reactants. The very low amount of Ru (0.1 wt %) with atomic dispersion boosts the catalytic performance of manganese oxides. Experimental and theoretical results show how the Ru sites enhance the ammonia resistance of the catalyst, bolstering its performance in alcohol dehydrogenation and oxygen activation, the key steps in the oxidative cyanation. This investigation demonstrates the high efficiency of a single-site Ru catalyst for nitrile production.
- Gates, Bruce C.,Guan, Erjia,Meng, Xiangju,Wang, Chengtao,Wang, Hai,Wang, Liang,Wang, Sai,Xiao, Feng-Shou,Xu, Dongyang,Xu, Hua,Yang, Bo,Zhang, Jian
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p. 6299 - 6308
(2020/07/21)
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- Identification of an Active NiCu Catalyst for Nitrile Synthesis from Alcohol
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Development of heterogeneous catalysts for alcohol transformation into nitriles under oxidant-free conditions is a challenge. Considering the C-H activation on α-carbon of primary alcohols is the rate-determining step, decreasing the activation energy of C-H activation is critical in order to enhance the catalytic activity. Several NiM/Al2O3 bimetallic catalysts were synthesized and scrutinized in catalytic transformation of 1-butanol to butyronitrile. Ni-Cu was identified as a suitable combination with the optimized Ni0.5Cu0.5/Al2O3 catalyst exhibiting 10 times higher turnover frequency than Ni/Al2O3 catalyst. X-ray absorption spectroscopy (XAS) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) revealed that the NiCu particles in the catalyst exist in the form of homogeneous alloys with an average size of 8.3 nm, providing an experimental foundation to build up a catalyst model for further density functional theory (DFT) calculations. Calculations were done over a series of NiM catalysts, and the experimentally observed activity trend could be rationalized by the Br?nsted-Evans-Polanyi (BEP) principle, i.e., catalysts that afford reduced reaction energy also feature lower activation barriers. The calculated activation energy (Ea) for C-H activation with coadsorbed NH3 dropped from 63.4 kJ/mol on pure Ni catalyst to 49.9 kJ/mol on the most active NiCu-2 site in NiCu bimetallic catalyst, in good agreement with the experimentally measured activation energy values. The Ni0.5Cu0.5/Al2O3 catalyst was further employed to convert 11 primary alcohols into nitriles with high to near-quantitative yields, at a Ni loading 10 times less than that of the conventional Ni/Al2O3 catalyst.
- Wang, Yunzhu,Furukawa, Shinya,Yan, Ning
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p. 6681 - 6691
(2019/07/12)
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- Oxidant free conversion of alcohols to nitriles over Ni-based catalysts
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Organic nitriles are significant and versatile industrial feedstocks, but their conventional synthetic protocols require hazardous starting materials and/or harsh reaction conditions posing environmental and health risks. Herein, we established a Ni-based catalytic system to convert primary alcohols to nitriles with ammonia gas as the sole nitrogen source under oxidant-free conditions at merely 190-230 °C. Based on isotope labelling experiments, in situ DRIFTS and control experiments, the reaction pathway was identified to follow a dehydrogenation-imination-dehydrogenation sequence, with α-carbon C-H bond breakage as the rate determining step. Ni is superior to all noble metal catalysts tested, due to its excellent dehydrogenation ability that is not inhibited by NH3. The support plays an auxiliary role, promoting the reaction between aldehyde and ammonia to form imine as a critical intermediate. Ni/Al2O3 catalyst prepared via a deposition-precipitation method, featuring both excellent dispersion of metallic Ni and suitable acid sites, enabled alcohol transformation into nitrile under unprecedented low temperature. Various alcohols were converted into their corresponding nitriles in high conversions and yields (both up to 99%), while the catalyst kept 90% of its original activity after 48 hours in the stability test, highlighting the wide applicability and the robustness of the catalytic system.
- Wang, Yunzhu,Furukawa, Shinya,Zhang, Zhang,Torrente-Murciano, Laura,Khan, Saif A.,Yan, Ning
-
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- Green synthesis of benzonitrile using ionic liquid with multiple roles as the recycling agent
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Preparation of benzonitrile from benzaldehyde and hydroxylamine hydrochloride is one of the most advantageous approaches. Nevertheless, it suffers from various constraints such as longer reaction time, corrosion and recovery of hydrochloric acid, the use of metal salt catalysts and their separation. For these reasons, a novel green benzonitrile synthetic route was proposed with ionic liquid as the recycling agent in this study. The results indicated that hydroxylamine 1-sulfobutyl pyridine hydrosulfate salt ((NH2OH)2·[HSO3-b-Py]·HSO4) was an expert alternative to hydroxylamine hydrochloride. Meanwhile, the ionic liquid [HSO3-b-Py]·HSO4 exhibited the multiple roles of co-solvent, catalysis and phase separation, thus the use of metal salt catalyst was eliminated, and no additional catalyst was needed. Hence, the separation process was greatly simplified. When the molar ratio of benzaldehyde to (NH2OH)2·[HSO3-b-Py]·HSO4 was 1:1.5, the volume ratio of paraxylene to [HSO3-b-Py]·HSO4 was 2:1, the benzaldehyde conversion and benzonitrile yield were both 100% at 120 °C in 2 h. Even better, the ionic liquid could be recovered easily by phase separation, and recycled directly after reaction. Additionally, this novel route is applicable to the green synthesis of a variety of aromatic, heteroaromatic and aliphatic nitriles with excellent yields.
- Li, Zhihui,Wang, Tingting,Qi, Xudong,Yang, Qiusheng,Gao, Liya,Zhang, Dongsheng,Zhao, Xinqiang,Wang, Yanji
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p. 17631 - 17638
(2019/06/24)
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- Extending the Chemistry of Hexamethylenetetramine in Ruthenium-Catalyzed Amine Oxidation
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A very efficient, highly atom economical, and environmentally benign oxidation of primary and secondary amines using an in situ catalyst system generated from commercially available ruthenium(II) benzene dichloride dimer and hexamethylenetetramine has been demonstrated. Mechanistic studies revealed that hexamethylenetetramine acted as a source of hydride to generate the active ruthenium hydride catalyst and amine oxidation involves a dehydrogenative pathway. In comparison to reported catalyst systems for the dehydrogenative oxidation of amines, this synthetic protocol makes use of a simple ruthenium precursor and a cheaper additive; it is very selective, leading to the exclusive formation of nitrile/imine compounds. Further, it releases hydrogen as the only side product, suggesting the potential application of the developed catalyst system in hydrogen storage.
- Kannan, Muthukumar,Muthaiah, Senthilkumar
-
supporting information
p. 3560 - 3567
(2019/11/13)
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- A method of synthesizing fatty nitrile by the aliphatic aldehyde
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The invention relates to a method of synthesizing fatty nitrile by the aliphatic aldehyde. The method comprises the following steps: the aliphatic aldehyde, ionic liquid regenerating and ionic liquid in the reactor, to join the two toluene, stirring, of the reflux condensation, in the normal pressure, 90 - 120 °C reaction under 0.5 - 2 h, to obtain the product fatty nitrile; wherein said ionic liquid is 1 - sulfobutyl pyridine bisulphate ionic liquid; ion liquid hydroxylamine salt is 1 - sulfobutyl pyridine bisulphate ion liquid hydroxylamine salt. The invention in one reactor to achieve the fat [...] and fat aldoxime dehydration integrated two-step reaction, the process is simple, easy to operate; to ionic liquid as catalyst and a co-solvent, without the addition of metal salt catalyst and corrosive solvent, environment-friendly.
- -
-
Paragraph 0027; 0028; 0047; 0048
(2019/05/28)
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- Mechanochemical Activation of Zinc and Application to Negishi Cross-Coupling
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A form independent activation of zinc, concomitant generation of organozinc species and engagement in a Negishi cross-coupling reaction via mechanochemical methods is reported. The reported method exhibits a broad substrate scope for both C(sp3)–C(sp2) and C(sp2)–C(sp2) couplings and is tolerant to many important functional groups. The method may offer broad reaching opportunities for the in situ generation organometallic compounds from base metals and their concomitant engagement in synthetic reactions via mechanochemical methods.
- Cao, Qun,Howard, Joseph L.,Wheatley, Emilie,Browne, Duncan L.
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p. 11339 - 11343
(2018/08/28)
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- Pd/Mn Bimetallic Relay Catalysis for Aerobic Aldoxime Dehydration to Nitriles
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A Pd/Mn bimetal system was found to be an effective catalyst for dehydration of aldoximes to the useful nitriles under mild aerobic conditions. Different to the known metal-catalyzed aldoxime dehydration reactions, this reaction very possibly proceeded via an alternative mechanism of Pd/Mn bimetal relay catalysis involving a Mn-catalyzed aerobic oxidation of aldoximes to nitrile oxides by air and a Pd-catalyzed oxygen transfer from the nitrile oxides to the solvent acetonitrile. This method tolerates a variety of substrates including sterically bulky ones and also the natural product derivative. (Figure presented.).
- Zhang, Dongliang,Huang, Yaping,Zhang, Erlei,Yi, Rong,Chen, Chao,Yu, Lei,Xu, Qing
-
supporting information
p. 784 - 790
(2018/01/04)
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- Cooperative Palladium/Lewis Acid-Catalyzed Transfer Hydrocyanation of Alkenes and Alkynes Using 1-Methylcyclohexa-2,5-diene-1-carbonitrile
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Catalytic transfer hydrocyanation represents a clean and safe alternative to hydrocyanation processes using toxic HCN gas. Such reactions provide access to pharmaceutically important nitrile derivatives starting with alkenes and alkynes. Herein, an efficient and practical cooperative palladium/Lewis acid-catalyzed transfer hydrocyanation of alkenes and alkynes is presented using 1-methylcyclohexa-2,5-diene-1-carbonitrile as a benign and readily available HCN source. A large set of nitrile derivatives (>50 examples) are prepared from both aliphatic and aromatic alkenes with good to excellent anti-Markovnikov selectivity. A range of aliphatic alkenes engage in selective hydrocyanation to provide the corresponding nitriles. The introduced method is useful for chain walking hydrocyanation of internal alkenes to afford terminal nitriles in good regioselectivities. This protocol is also applicable to late-stage modification of bioactive molecules.
- Bhunia, Anup,Bergander, Klaus,Studer, Armido
-
supporting information
p. 16353 - 16359
(2018/11/25)
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- A mineralogically-inspired silver-bismuth hybrid material: An efficient heterogeneous catalyst for the direct synthesis of nitriles from terminal alkynes
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The synthesis and characterization of a silver-containing hybrid material is reported as a novel heterogeneous noble metal catalyst. In order to eliminate the need for traditional immobilization techniques, and to create a solid material with structurally-bound silver catalytic centers, the layered structure of a naturally occurring mineral served as the basis of the initial catalyst design. The novel material was prepared by means of the urea-mediated homogeneous precipitation of the corresponding metal nitrates, and was fully characterized by means of diverse instrumental techniques (X-ray diffractometry, Raman, IR, UV-Vis, EPR, X-ray photoelectron spectroscopies, thermal methods as well as atomic force, scanning and transmission electron microscopies). The as-prepared material exhibited outstanding activity in silver-catalyzed CC bond activation to yield organic nitriles directly from terminal alkynes with less environmental concerns as compared to the classical synthesis methods. The effects of the reaction time, the temperature, as well as the role of various solvents, nitrogen sources and additives were carefully scrutinized in order to achieve high-yielding and selective nitrile formation. The heterogeneous nature of the reaction was verified and the solid catalyst was recycled and reused numerous times without loss of its activity or degradation of its structure, thereby offering a sustainable synthetic methodology.
- ?tv?s, Sándor B.,Mészáros, Rebeka,Varga, Gábor,Kocsis, Marianna,Kónya, Zoltán,Kukovecz, ákos,Pusztai, Péter,Sipos, Pál,Pálinkó, István,Fül?p, Ferenc
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p. 1007 - 1019
(2018/03/13)
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- p-TsOH mediated solvent and metal catalyst free synthesis of nitriles from aldehydes via Schmidt reaction
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A new and efficient protocol for the conversion of aldehyde into nitriles by modified Schmidt reaction. The reaction is carried out under solvent free condition using sodium azide as a source of nitrogen and catalysed by p-toluene sulphonic acid in presence of silica surface with no side product. This transformation gives good to excellent yield for numerous aromatic, aliphatic and heterocyclic nitriles using very simple reagent. This method has avoided the use of transition metal catalyst, toxic cyanide, hazardous solvent and offers a greener, simple and environment friendly procedure.
- Mitra, Bijeta,Pariyar, Gyan Chandra,Singha, Rabindranath,Ghosh, Pranab
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supporting information
p. 2298 - 2301
(2017/05/19)
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- Poly(ethylene glycol)–bound sulfonyl chloride as an efficient catalyst for transformation of aldoximes to nitriles
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An operationally simple, efficient, and environmentally benign preparation of nitriles in good to excellent yields from various aldoximes in the presence of recyclable poly(ethylene glycol)–bound sulfonyl chloride is described.
- Zhang, Xiao-Lan,Liu, Xiao-Ling,Sang, Xiao-Yan,Sheng, Shou-Ri
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p. 232 - 237
(2017/01/22)
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- A method of synthesizing all hair (by machine translation)
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The invention relates to a method of synthesizing all hair, which belongs to the technical field of organic synthesis. In order to market and common enanthaldehyde preparation on raw materials (enanthaldehyde preparation is castor oil cracking by-product, source sufficient), and hydroxylamine reaction generating aldoxime, aldoxime further dehydration to obtain age nitrile, the age nitrile passes through hydrogenation to obtain the hair loss. In accordance with the invention described from the enanthaldehyde preparation process to age nitrile reaction process has the advantages of simple and convenient operation, mild condition, material consumption and energy consumption and the like, and more in line with the concept of green chemical industry; the invention prepared by the hair loss not only content is high, and the quality is good, selective stability. (by machine translation)
- -
-
Paragraph 0036; 0037
(2018/03/01)
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- Polyethylene glycol supported phosphorus chloride: An efficient and recyclable catalyst for the preparation of nitriles from aldoximes
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Polyethylene glycol (PEG) supported phosphorus chloride has been developed and used as an efficient and recyclable catalyst for dehydration of various aldoximes into the corresponding nitriles. This protocol has many advantages such as high conversion, high selectivity, short reaction time, mild reaction conditions, and simple experimental procedure.
- Zhang, Xiao-Lan,Sheng, Shou-Ri,Wei, Mei-Hong,Liu, Xiao-Ling
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p. 513 - 517
(2017/05/01)
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- MANUFACTURING METHOD OF NITRYL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for manufacturing a nitryl compound at good efficiency and safety under a moderate reaction condition. SOLUTION: In a manufacturing method of a nitryl compound, an organic compound having a carbon-carbon unsaturated bond and acetone cyanhydrin are reacted in the presence of bivalent nickel compound, an organic phosphorus compound and a metal powder to add a nitryl group to one carbon constituting the carbon-carbon unsaturated bond. The metal powder is selected from zinc, magnesium, aluminum and manganese. The nickel compound is preferably halide salt of nickel, carboxylate of nickel and β-diketo compound salt of nickel. The organic phosphorus compound is preferably triphenylphosphine. The reaction between the organic compound and the acetone cyanhydrin can be conducted at a reaction temperature of 85°C to 90°C in a solvent of an alcohol compound. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
- -
-
Paragraph 0051-0052
(2017/04/27)
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- Fe3O4-nanoparticles catalyzed an efficient synthesis of nitriles from aldehydes
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Fe3O4-CTAB NPs have been applied as a competent catalyst for one-pot synthesis of nitriles directly from aldehydes. The present investigation describes the synthesis of nitriles by combination of aromatic/aliphatic/heterocyclic aldehydes and hydroxylamine hydrochloride in the presence of iron oxide nanocatalyst in DMF under reflux condition. Fe3O4-CTAB NPs were prepared by reported method and characterized by FE-SEM, TEM, and XRD analysis. The amount of Fe in Fe3O4-CTAB was quantified by Atomic Absorption Spectroscopy (AAS). The protocol endow with excellent yield of products along with simple reaction set up and economically adept alternative approach.
- Ghosh, Pranab,Saha, Bittu,Pariyar, Gyan Chandra,Tamang, Abiral,Subba, Raju
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supporting information
p. 3618 - 3621
(2016/07/21)
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- Nanocrystalline CeO2 as a Highly Active and Selective Catalyst for the Dehydration of Aldoximes to Nitriles and One-Pot Synthesis of Amides and Esters
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The dehydration of aldoximes into nitriles has been performed in the presence of various metal oxides with different acid-base properties (Al2O3, TiO2, CeO2, MgO). The results showed that a nanocrystalline CeO2 was the most active catalyst. An in situ IR spectroscopy study supports a polar elimination mechanism in the dehydration of aldoxime on metal oxide catalysts, in which Lewis acid sites and basic sites are involved. The Lewis acid sites intervene in the adsorption of the oxime on the catalyst surface while surface base sites are responsible for the C1-H bond cleavage. Thus, the acid-base properties of nanocrystalline CeO2 are responsible for the high catalytic activity and selectivity. A variety of aldoximes including alkyl and cycloalkyl aldoximes have been dehydrated into the corresponding nitriles in good yields (80-97%) using nanosized ceria which moreover resulted in a stable and reusable catalyst. Additionally, it has been showed that a variety of pharmacologically important products such as picolinamide and picolinic acid alkyl ester derivatives can be obtained in good yields from 2-pyridinaldoxime in a one-pot process using the nanoceria as catalyst.
- Rapeyko, Anastasia,Climent, Maria J.,Corma, Avelino,Concepción, Patricia,Iborra, Sara
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p. 4564 - 4575
(2016/07/12)
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- Amino acid derived ionic liquid supported iron Schiff base catalyzed greener approach for the aerobic oxidation of amines to nitriles
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Amino acid dl-threonine derived ionic liquid was treated with salicylaldehyde to give corresponding Schiff base which subsequently is complexed with iron and used as a green catalyst for aerobic oxidation of amines under solvent-less conditions. The developed catalyst was readily synthesized, reusable, and exhibited superior catalytic activity owing to the synergistic effect of ionic liquid moiety. The developed catalyst was found to be quite stable and could be reused for several runs without any significant loss in catalytic activity.
- Varyani, Manish,Khatri, Praveen K.,Jain, Suman L.
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p. 723 - 727
(2016/02/09)
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- Half-Sandwich Guanidinate-Osmium(II) Complexes: Synthesis and Application in the Selective Dehydration of Aldoximes
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The novel guanidinate-osmium(II) complexes [OsCl{κ2-(N,N′)-C(NR)(NiPr)NHiPr}(η6-p-cymene)] [R = Ph (3a), 4-C6H4F (3b), 4-C6H4Cl (3c), 4-C6H4CF3 (3d), 3-C6H4CF3 (3e), 3,5-C6H3(CF3)2 (3f), 4-C6H4CN (3g), 4-C6H4Me (3h), 3-C6H4Me (3i), 2-C6H4Me (3j), 4-C6H4tBu (3k), 2,6-C6H3iPr2 (3l), 2,4,6-C6H2Me3 (3m)] have been synthesized in high yields (70-88 %) by treatment of THF solutions of the dimeric precursor [{OsCl(μ-Cl)(η6-p-cymene)}2] (1) with 4 equivalents of the corresponding guanidine (iPrHN)2C=NR (2a-m) at room temperature. The easily separable guanidinium chloride salts [(iPrHN)2C(NHR)]Cl (4a-m) were also formed in these reactions. The structures of 3a, 3d, and 3h were unequivocally confirmed by X-ray diffraction methods. Complexes 3a-m proved to be active in the catalytic dehydration of aldoximes. The best results were obtained with [OsCl{κ2-(N,N′)-C(N-4-C6H4CF3)(NiPr)NHiPr}(η6-p-cymene)] (3d; 5 mol-%), which, in acetonitrile at 80C, was able to convert selectively a large variety of aromatic, heteroaromatic, α,β-unsaturated, and aliphatic aldoximes into the corresponding nitriles in high yields and short reaction times. Novel osmium(II)-guanidinate complexes of general composition [OsCl{κ2-(N,N′)-C(NR)(NiPr)NHiPr}(η6-p-cymene)] (R = Ar) have been synthesized and successfully employed as catalysts for the selective conversion of aldoximes into nitriles.
- Francos, Javier,González-Liste, Pedro J.,Menéndez-Rodríguez, Lucía,Crochet, Pascale,Cadierno, Victorio,Borge, Javier,Anti?olo, Antonio,Fernández-Galán, Rafael,Carrillo-Hermosilla, Fernando
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p. 393 - 402
(2016/02/03)
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- Impact of structured catalysts in amine oxidation under mild conditions
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A structured graphene/graphite catalyst grown on a commercial austenitic stainless steel sheet providing a micromonolith was obtained by submitting the nude stainless steel structure to a carbon-rich atmosphere (first 300 mL/min of a reductive H2/N2 (1:1) flow, then to 180 mL/min of a CH4/H2 (1:5)) at high temperature (900 °C) for 2 h. The preparation procedure resulted in a homogenous surface coated with a carbon-rich film as observed by EDX and SEM images. Further characterizations by Raman spectroscopy revealed characteristic Raman lines of graphene and crystalline graphite disposed in a hierarchical organization. The disposal of the obtained surface layers was also confirmed by grazing incidence X-ray diffraction. Besides this, XRD indicated the overlapping diffraction lines of graphite, cementite and M7C3 carbides. The graphene nature of the outermost layer was also confirmed by XPS. The catalytic behavior of the structured graphene/graphite catalyst was evaluated in the selective oxidation of heptylamine. At 200 °C it afforded a total conversion with a combined selectivity in heptanonitrile and N-heptylidene-heptylamine of 67% (10% heptanonitrile) that corresponds indeed to a very efficient system in the absence of any metal. Kinetic experiments with the scope to calculate the activation energies were also performed.
- Santos, Jose Luis,Navarro, Pablo,Odriozola, Jose Antonio,Centeno, Miguel Angel,Pavel, Octavian D.,Jurca, Bogdan,Parvulescu, Vasile I.
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p. 266 - 272
(2016/11/29)
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- Efficient nickel-catalyzed hydrocyanation of alkenes using acetone cyanohydrin as a safer cyano source
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An active nickel catalyst prepared in situ from a Ni(II) compound, phosphine ligand, and zinc powder was found to be an efficient catalyst system for the hydrocyanation of various alkenes using acetone cyanohydrin as a safer cyano source. The combination of NiCl2·6H2O and 1,3-bis(diphenylphosphino)propane was the most efficient catalyst precursor in DMF. Under the optimized conditions, various styrenes, heterocyclic alkenes, and aliphatic alkenes were converted to their corresponding nitriles in excellent yields.
- Nemoto, Koji,Nagafuchi, Tsuyoshi,Tominaga, Ken-ichi,Sato, Kazuhiko
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p. 3199 - 3203
(2016/07/06)
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- Graphene oxide as a metal-free catalyst for oxidation of primary amines to nitriles by hypochlorite
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Graphene oxide catalyzes oxidation by NaClO of primary benzyl and aliphatic amines to a product distribution comprising nitriles and imines. Nitriles are the sole product for long chain aliphatic amines. Spectroscopic characterization suggests that percarboxylic and perlactone groups could be the active sites of the process.
- Primo, Ana,Puche, Marta,Pavel, Octavian D.,Cojocaru, Bogdan,Tirsoaga, Alina,Parvulescu, Vasile,García, Hermenegildo
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p. 1839 - 1842
(2016/02/12)
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- Catalytic Hydrogen Production by Ruthenium Complexes from the Conversion of Primary Amines to Nitriles: Potential Application as a Liquid Organic Hydrogen Carrier
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The potential application of the primary amine/nitrile pair as a liquid organic hydrogen carrier (LOHC) has been evaluated. Ruthenium complexes of formula [(p-cym)Ru(NHC)Cl2] (NHC=N-heterocyclic carbene) catalyze the acceptorless dehydrogenation of primary amines to nitriles with the formation of molecular hydrogen. Notably, the reaction proceeds without any external additive, under air, and under mild reaction conditions. The catalytic properties of a ruthenium complex supported on the surface of graphene have been explored for reutilization purposes. The ruthenium-supported catalyst is active for at least 10 runs without any apparent loss of activity. The results obtained in terms of catalytic activity, stability, and recyclability are encouraging for the potential application of the amine/nitrile pair as a LOHC. The main challenge in the dehydrogenation of benzylamines is the selectivity control, such as avoiding the formation of imine byproducts due to transamination reactions. Herein, selectivity has been achieved by using long-chain primary amines such as dodecylamine. Mechanistic studies have been performed to rationalize the key factors involved in the activity and selectivity of the catalysts in the dehydrogenation of amines. The experimental results suggest that the catalyst resting state contains a coordinated amine.
- Ventura-Espinosa, David,Marzá-Beltrán, Aida,Mata, Jose A.
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p. 17758 - 17766
(2016/11/28)
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- Transition-Metal-Free Deacylative Cleavage of Unstrained C(sp3)-C(sp2) Bonds: Cyanide-Free Access to Aryl and Aliphatic Nitriles from Ketones and Aldehydes
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A transition-metal-free deacylative C(sp3)-C(sp2) bond cleavage for the synthetically practical oxidative amination of ketones and aldehydes to nitriles is first described, using cheap and commercially abundant NaNO2 as the oxidant and the nitrogen source. Various nitriles bearing aryl, heteroaryl, alkyl, and alkenyl groups could be smoothly obtained from ketones and aldehydes in high yields, avoiding highly toxic cyanides or transition metals.
- Ge, Jing-Jie,Yao, Chuan-Zhi,Wang, Mei-Mei,Zheng, Hong-Xing,Kang, Yan-Biao,Li, Yadong
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supporting information
p. 228 - 231
(2016/02/03)
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- Palladium(II) complexes with a phosphino-oxime ligand: Synthesis, structure and applications to the catalytic rearrangement and dehydration of aldoximes
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The treatment of [PdCl2(COD)] (COD = 1,5-cyclooctadiene) with 1 and 2 equivalents of 2-(diphenylphosphino)benzaldehyde oxime in dichloromethane at room temperature led to the selective formation of [PdCl2{κ2-(P,N)-2-Ph2PC6H4CHNOH}] (1) and [Pd{κ2-(P,N)-2-Ph2PC6H4CHNOH}2][Cl]2 (2), respectively, which represent the first examples of Pd(II) complexes containing a phosphino-oxime ligand. These compounds, whose structures were fully confirmed by X-ray diffraction methods, were active in the catalytic rearrangement of aldoximes. In particular, using 5 mol% complex 1, a large variety of aldoximes could be cleanly converted into the corresponding primary amides at 100 °C, employing water as solvent and without the assistance of any cocatalyst. Palladium nanoparticles are the active species in the rearrangement process. In addition, when the same reactions were performed employing acetonitrile as solvent, selective dehydration of the aldoximes to form the respective nitriles was observed. For comparative purposes, the catalytic behaviour of an oxime-derived palladacyclic complex has also been briefly evaluated.
- Menéndez-Rodríguez, Lucía,Tomás-Mendivil, Eder,Francos, Javier,Nájera, Carmen,Crochet, Pascale,Cadierno, Victorio
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p. 3754 - 3761
(2015/07/01)
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- One-step synthesis of nitriles by the dehydrogenation-amination of fatty primary alcohols over Cu/m-ZrO2
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An effective method for one-step synthesis of nitriles employing C 2-C8 fatty primary alcohols and ammonia over 5%Cu/m-ZrO2 has been found. The conversion of alcohols and selectivity of nitriles obtained are > 96 and > 87 wt.%, respectively, and are obviously influenced by the C2-substitution rather than the chain length of fatty primary alcohols. Cu/m-ZrO2 was characterized by XRD, H 2-TPR, CO2-TPD and NH3-TPD. It is revealed that a substantial amount of Cu species over m-ZrO2 is in highly dispersed CuO. A plausible mechanism is proposed and supported by different experiments, and aldehyde generation is an important step in the reaction mechanism.
- Hu, Yunfeng,Jin, Shuhan,Zhang, Zhichao,Zhang, Likun,Deng, Jun,Zhang, Hongsheng
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- Ac2O/K2CO3/DMSO: An efficient and practical reagent system for the synthesis of nitriles from aldoximes
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The transformation of aldoximes to nitriles using acetic anhydride as dehydration agent under mild reaction conditions is reported. The reaction, which proceeds under weak alkaline condition, allows for the conversion of a range of aldoximes including aromatic aldoximes, alphatic aldoximes, and heterocyclic aldoximes in good to excellent yields. This method has also been successfully applied to the synthesis of calcium channel blocker nilvadipine in pilot scale.
- Song, Yaoping,Shen, Dongguo,Zhang, Qinghua,Chen, Bo,Xu, Guangyu
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p. 639 - 641
(2014/01/23)
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- Self-catalyzed direct amidation of ketones: A sustainable procedure for acetaminophen synthesis
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High yielding amination of ketones and benzaldehyde in acid-less conditions has been conducted on several ketones to achieve amides and nitriles. The reactivity of the selected substrates showed to depend on both oximation and Beckmann rearrangement reaction rates. Oximation allows the in-situ production of hydrochloric acid that enables Beckmann rearrangement of the oxime to form the corresponding amide or nitrile. It is noteworthy that, using this one-pot synthetic approach, N-acetyl-4-aminophenol (acetaminophen drug), can be easily synthesized starting from 4-hydroxy-acetophenone in high yield. Acetanilide and ε-caprolactam can be also efficiently synthesized employing this synthetic procedure.
- Rancan, Elia,Aricò, Fabio,Quartarone, Giuseppe,Ronchin, Lucio,Tundo, Pietro,Vavasori, Andrea
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- Self-catalyzed direct amidation of ketones: A sustainable procedure for acetaminophen synthesis
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High yielding amination of ketones and benzaldehyde in acid-less conditions has been conducted on several ketones to achieve amides and nitriles. The reactivity of the selected substrates showed to depend on both oximation and Beckmann rearrangement reaction rates. Oximation allows the in-situ production of hydrochloric acid that enables Beckmann rearrangement of the oxime to form the corresponding amide or nitrile. It is noteworthy that, using this one-pot synthetic approach, N-acetyl-4-aminophenol (acetaminophen drug), can be easily synthesized starting from 4-hydroxy-acetophenone in high yield. Acetanilide and ε-caprolactam can be also efficiently synthesized employing this synthetic procedure.
- Rancan, Elia,Aricò, Fabio,Quartarone, Giuseppe,Ronchin, Lucio,Tundo, Pietro,Vavasori, Andrea
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- Organoselenium-catalyzed mild dehydration of aldoximes: An unexpected practical method for organonitrile synthesis
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Areneselenenic acids (ArSeOH), readily generated from diaryl diselenides and H2O2 by in situ oxidation, were found to be effective and reusable catalysts for dehydration of aldoximes, leading to a practical and scalable preparation of useful organonitriles under mild conditions.
- Yu, Lei,Li, Hongyan,Zhang, Xu,Ye, Jianqing,Liu, Jianping,Xu, Qing,Lautens, Mark
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supporting information
p. 1346 - 1349
(2014/04/03)
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- Direct synthesis of nitriles from aldehydes using chloramine-T/KI in aqueous ammonia
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A convenient method for direct conversion of aldehydes into nitriles has been developed using chloramine-T/KI in aqueous ammonia.
- Zhu, Yi-Zhong,Zhang, Xi-Quan,Liu, Fei,Gu, Hong-Mei,Zhu, Hai-Liang
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supporting information
p. 2943 - 2948
(2013/09/02)
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- An efficient, rapid and facile procedure for conversion of aldoximes to nitriles using triphenylphosphine and N-halo sulfonamides
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N,N,N′,N′-Tetrabromobenzene-1,3-disulfonamide (TBBDA)/triphenylphosphine and N,N,N′,N′-tetrachlorobenzene-1,3- disulfonamide (TCBDA)/triphenylphosphine have been introduced as highly efficient systems for the versatile conversion of aldoxime derivatives into nitriles. The process reported here is operationally simple and reactions have been mildly performed in dichloromethane at room temperature.
- Ghorbani-Vaghei, Ramin,Shiri, Lotfi,Ghorbani-Choghamarani, Arash
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p. 1123 - 1126
(2014/01/06)
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- Silver-catalyzed nitrogenation of alkynes: A direct approach to nitriles through C≡C bond cleavage
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Three in one blow! A novel direct transformation of alkynes into nitriles by a silver-catalyzed nitrogenation reaction through C≡C bond cleavage has been developed. This research provides both a new application for alkynes in organic synthesis, and valuable mechanistic insights into nitrogenation chemistry. Copyright
- Shen, Tao,Wang, Teng,Qin, Chong,Jiao, Ning
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supporting information
p. 6677 - 6680
(2013/07/25)
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- Ruthenium-catalyzed one-pot synthesis of primary amides from aldehydes in water
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The readily available arene-ruthenium(ii) complex [RuCl2(η 6-C6Me6){P(NMe2)3}] (5 mol%) proved to be an efficient catalyst for the direct synthesis of primary amides from aldehydes and hydroxylamine hydrochloride (NH2OH· HCl) in water at 100 °C. The process, which requires the presence of NaHCO3 to catch the HCl released during the formation of the key aldoxime intermediates, was operative with both aromatic, heteroaromatic, α,β-unsaturated and aliphatic aldehydes, and tolerated several functional groups. A greener approach using commercially available NH 2OH solution (50 wt.% in water) is also presented.
- Garcia-Alvarez, Rocio,Diaz-Alvarez, Alba E.,Crochet, Pascale,Cadierno, Victorio
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p. 5889 - 5894
(2013/05/09)
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- One pot synthesis of nitriles from aldehydes and hydroxylamine hydrochloride using ferrous sulphate in DMF under reflux condition
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A rapid and facile one pot synthesis of nitrile has been carried out in high yields from the corresponding aldehydes and hydroxylamine hydrochloride in the presence of anhydrous ferrous sulphate and DMF under reflux condition.
- Patil, Dinanath D.,Wadhava, Gurumeet C.,Deshmukh, Arun K.
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experimental part
p. 1401 - 1402
(2012/08/28)
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- Selective conversion of aldehydes into nitriles and primary amides in aqueous media
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A simple and selective conversion of aldehydes into the corresponding nitriles and primary amides in aqueous ammonia has been developed. The aldehydes were efficiently converted to the corresponding nitriles in moderate to excellent yields using tetrabutylammonium iodide/tert-butyl hydroperoxide system. The primary amides, however, can be selectively synthesised only in the presence of tert-butyl hydroperoxide.
- Wang, Liang,Shen, Chen,Wang, Hai-Ping,Zhou, Wei-You,Sun, Fu-An,He, Ming-Yang,Chen, Qun
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p. 460 - 462
(2012/10/29)
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- Iron-catalyzed alkyl-alkyl Suzuki-Miyaura coupling
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Chemoselective Suzuki-Miyaura coupling of primary and secondary alkyl halides is realized by using an iron/Xantphos catalyst. Primary and secondary alkyl bromides undergo the reaction to give the coupling products in good yields. Application to the synthe
- Hatakeyama, Takuji,Hashimoto, Toru,Kathriarachchi, Kalum K. A. D. S.,Zenmyo, Takeshi,Seike, Hirofumi,Nakamura, Masaharu
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supporting information; experimental part
p. 8834 - 8837
(2012/10/08)
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- Microwave promoted rapid dehydration of aldoximes to nitriles using melamine-formaldehyde resin supported sulphuric acid in dry media
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A simple and convenient procedure for the synthesis of nitriles by dehydration of aldoxime using supported sulphuric acid on melamine-formaldehyde resin (MFR) under solvent-free condition has been developed. A variety of aromatic and aliphatic aldoximes were converted to the corresponding nitriles. The resin was recovered and reused for subsequent reactions.
- Rezaei, Ramin,Karami, Marzeih
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experimental part
p. 815 - 818
(2012/01/06)
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- Copper-catalyzed rearrangement of oximes into primary amides
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The atom-efficient and cost-effective rearrangement of oximes into primary amides is catalyzed by simple copper salts. The use of homogeneous Cu(OAc) 2 (1-2 mol %) was found to be effective for this transformation at 80 °C. The reaction was successful with either conventional or microwave heating. CuO and CuO/ZnO on activated carbon provided a competent reuseable heterogeneous catalyst which could be used in a batch process or in flow. Copper salts are much cheaper than the precious metals previously used for this rearrangement, and the reaction conditions are milder than those reported.
- Sharma, Sumeet K.,Bishopp, Simon D.,Liana Allen,Lawrence, Ruth,Bamford, Mark J.,Lapkin, Alexei A.,Plucinski, Pawel,Watson, Robert J.,Williams, Jonathan M.J.
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supporting information; experimental part
p. 4252 - 4255
(2011/08/22)
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- Direct synthesis of nitriles from aldehydes using tetrabutylammonium tribromide in aqueous ammonia
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A convenient method for direct conversion of aldehydes into nitriles has been developed by using tetrabutylammonium tribromide in aqueous ammonia. Springer-Verlag 2010.
- Zhu, Yi-Zhong,Cai, Chun
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experimental part
p. 637 - 639
(2011/04/25)
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- A facile one-pot conversion of aldehydes into nitriles
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A facile one-pot synthesis of nitriles starting with aldehydes has been developed employing hydroxylamine hydrochloride in dimethylsulfoxide at 100C.
- Chill, Samuel T.,Mebane, Robert C.
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scheme or table
p. 3601 - 3606
(2009/12/04)
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- IBX/TBAB-mediated oxidation of primary amines to nitriles
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The combination of o-iodoxybenzoic acid (IBX) and tetrabutylammonium bromide (TBAB) efficiently oxidizes primary amines to the corresponding nitriles in good to excellent yield under mild conditions. The reaction is racemization-free when applied to a chiral lysine derivative. Georg Thieme Verlag Stuttgart.
- Drouet, Fleur,Fontaine, Patrice,Masson, Geraldine,Zhu, Jieping
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experimental part
p. 1370 - 1374
(2010/01/13)
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- Ionic liquid-promoted dehydration of aldoximes: a convenient access to aromatic, heteroaromatic and aliphatic nitriles
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A simple and convenient procedure for the synthesis of nitriles by dehydration of aldoximes using an ionic liquid, 1-pentyl-3-methylimidazolium tetrafluoroborate, [pmim]BF4 under organic solvent-free condition, has been developed. A variety of aromatic, heteroaromatic and aliphatic aldoximes are converted to the corresponding nitriles. The ionic liquid is recovered and reused for subsequent reactions.
- Saha, Debasree,Saha, Amit,Ranu, Brindaban C.
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experimental part
p. 6088 - 6091
(2010/03/03)
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- Conversion of aldoximes into nitriles with raney nickel in refluxing 2-propanol
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Aldoximes are readily dehydrated to nitriles with Raney nickel in refluxing 2-propanol. Copyright Taylor & Francis Group, LLC.
- Zuidema, Daniel R.,Dennison, Ami L.,Park, Elizabeth Y.,Mebane, Robert C.
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p. 3810 - 3815
(2008/12/23)
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