- Mesoporous silica gel as an effective and eco-friendly catalyst for highly selective preparation of cyclohexanone oxime by vapor phase oxidation of cyclohexylamine with air
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A simple and environmentally benign approach to highly selective preparation of cyclohexanone oxime by vapor phase catalytic oxidation of cyclohexylamine with air over mesoporous silica gel under atmospheric pressure has been successfully developed in this work. The results demonstrate that the nonmetallic mesoporous silica gel is an effective and eco-friendly catalyst for the vapor phase selective oxidation of cyclohexylamine to cyclohexanone oxime and the surface silicon hydroxyl groups as active sites are responsible for the excellent catalytic performance of silica gel. The present silica gel catalyst has advantages of low cost, long-time stable reactivity, easy regeneration, and reusability. This method employing inexpensive mesoporous silica gel as catalyst and air as green terminal oxidant under facile conditions is a promising process and has the potential to enable sustainable production of cyclohexanone oxime from the selective oxidation of cyclohexylamine with air in industrial applications.
- Liu, Shuilin,You, Kuiyi,Jian, Jian,Zhao, Fangfang,Zhong, Wenzhou,Yin, Dulin,Liu, Pingle,Ai, Qiuhong,Luo, He'an
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- An investigation into cyclohexanone ammoximation over Ti-MWW in a continuous slurry reactor
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In the present study, the liquid-phase ammoximation of cyclohexanone with ammonia and hydrogen peroxide was studied using a MWW-type titanosilicate (Ti-MWW) catalyst in a continuous slurry reactor to develop a clean process for producing cyclohexanone oxime. The reaction parameters, which governed the cyclohexanone conversion, oxime selectivity and catalyst deactivation, were investigated by simulating the operating conditions of an industrial process. Under optimized reaction conditions, Ti-MWW produced a cyclohexanone conversion and oxime selectivity over 96% and 99%, respectively. Moreover, Ti-MWW was extremely robust and showed a longer lifetime than the conventional titanium silicalite-1 catalyst. The causes of deactivation were elucidated to be the coke deposition and partial dissolution of the zeolite framework of Ti-MWW during ammoximation. The deactivated Ti-MWW catalyst was regenerated effectively by a combination of acid treatment and cyclic amine-assisted structural rearrangement.
- Zhao, Song,Xie, Wei,Yang, Junxia,Liu, Yueming,Zhang, Yingtian,Xu, Biliang,Jiang, Jin-Gang,He, Mingyuan,Wu, Peng
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- Preparation of cyclic ketoximes using aqueous hydroxylamine in ionic liquids
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Cyclohexanone oxime (the precursor for making ε-caprolactam) is readily prepared from cyclohexanone using aqueous hydroxylamine in ionic liquids.
- Ren, Rex X,Ou, Wei
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- A new route to lactam precursors from cycloalkanes: Direct production of nitrosocycloalkanes or cycloalkanone oximes by using tert-Butyl nitrite and N-hydroxyphthalimide
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Clean and selective: Nitrosation and oximation of cycloalkanes was achieved by treating them with tBuONO under Ar in the presente presence of a catalytic amount of N-hydroxyphthalimide (see scheme). The novel, clean nitrosation procedure uses halogen-free, relatively mild reaction conditions and results in good product selectivity (almost no organic byproducts) and high recovery of the catalyst.
- Hirabayashi, Tomotaka,Sakaguchi, Satoshi,Ishii, Yasutaka
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- A novel hydroxylamine ionic liquid salt resulting from the stabilization of NH2OH by a SO3H-functionalized ionic liquid
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A SO3H-functionalized ionic liquid was used as an alternative to conventional inorganic acids in hydroxylamine stabilization, leading to the formation of a novel hydroxylamine ionic liquid salt that exhibits improved thermal stability and reactivity in the one-step, solvent-free synthesis of caprolactam in comparison with hydroxylamine hydrochloride and hydroxylamine sulfate.
- Li, Zhihui,Yang, Qiusheng,Qi, Xudong,Xu, Yuanyuan,Zhang, Dongsheng,Wang, Yanji,Zhao, Xinqiang
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- Direct cyclohexanone oxime synthesis: Via oxidation-oximization of cyclohexane with ammonium acetate
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An unexpected cascade reaction for oxidation-oximization of cyclohexane with ammonium acetate was developed for the first time to access cyclohexanone oxime with 50.7% selectivity (13.6% conversion). Tetrahedral Ti sites in Ni-containing hollow titanium silicalite can serve as bifunctional catalytic centers in the reaction. This methodology not only provides a direct approach to prepare cyclohexanone oxime, but also simplifies process chemistry. Various available nitrogen sources, such as ammonium salt and even ammonia can be used as starting materials.
- Peng, Ling,Liu, Chan,Li, Na,Zhong, Wenzhou,Mao, Liqiu,Kirk, Steven Robert,Yin, Dulin
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- A clean conversion of carbonyl compounds to oximes using silica gel supported hydroxylamine hydrochloride
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The efficient condensation of carbonyl compounds with hydroxylamine hydrochloride under solvent free conditions is described.
- Kiasat, Ali Reza,Kazemi, Foad,Nourbakhsh, Kazem
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- Selective heterocyclic amidine inhibitors of human inducible nitric oxide synthase
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The potency and selectivity of a series of 5-hetero-2-iminohexahydroazepines were examined as inhibitors of the three human NOS isoforms. The effect of ring substitution of the 5-carbon for a heteroatom is presented. Potencies (IC50's) for these inhibitors are in the low micromolar range for hi-NOS with some examples exhibiting a 500× selectivity versus hec-NOS.
- Moormann, Alan E.,Metz, Sue,Toth, Mihaly V.,Moore, William M.,Jerome, Gina,Kornmeier, Christine,Manning, Pamela,Hansen Jr., Donald W.,Pitzele, Barnett S.,Webber
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- Mercury-catalyzed rearrangement of ketoximes into amides and lactams in acetonitrile
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(Chemical Equation Presented) An acetonitrile solution of mercury(II) chloride has been found to catalyze efficiently the conversion of a diverse range of ketoximes into their corresponding amides/lactams.
- Ramalingan, Chennan,Park, Yong-Tae
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- Pd/C Catalyzed selective hydrogenation of nitrobenzene to cyclohexanone oxime in the presence of NH2OH·HCl: Influence of the operative variables and insights on the reaction mechanism
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We studied the influence of temperature, solvent, pressure, catalysts type on the selectivity of nitrobenzene hydrogenation to cyclohexanone oxime (COX) in the presence of NH2OH. The best reaction conditions are: pressure 0.8 MPa, temperature 333 K, solvent ethers, and catalyst Pd/C5%. Other hydrogenation metal catalysts did not give comparable results. The amount of Pd/C influences the yield in COX, which rises above to 90 % at the highest load. The reaction profile shows that aniline is the reaction intermediate. Indeed, aniline as a substrate gives COX, though in lower yield than that achieved employing nitrobenzene. The NH2OH parallel hydrogenation to NH4Cl, influences positively the selectivity to COX. It has been observed that COX, cyclohexanone and N-cyclohexylideneaniline are in equilibrium in the reaction solution and all likely derive from nucleophilic substitutions to a common imine intermediate formed on the Pd surface, whose high activity does not need any further metal catalyst.
- Pietrobon, L.,Pontello, R.,Ronchin, L.,Sadraoui, C.,Tosetto, C.,Vavasori, A.
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- Atypical and Asymmetric 1,3-P,N Ligands: Synthesis, Coordination and Catalytic Performance of Cycloiminophosphanes
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Novel seven-membered cyclic imine-based 1,3-P,N ligands were obtained by capturing a Beckmann nitrilium ion intermediate generated in situ from cyclohexanone with benzotriazole, and then displacing it by a secondary phosphane under triflic acid promotion. These “cycloiminophosphanes” possess flexible non-isomerizable tetrahydroazepine rings with a high basicity; this sets them apart from previously reported iminophophanes. The donor strength of the ligands was investigated by using their P-κ1- and P,N-κ2-tungsten(0) carbonyl complexes, by determining the IR frequency of the trans-CO ligands. Complexes with [RhCp*Cl2]2 demonstrated the hemilability of the ligands, giving a dynamic equilibrium of κ1 and κ2 species; treatment with AgOTf gives full conversion to the κ2 complex. The potential for catalysis was shown in the RuII-catalyzed, solvent-free hydration of benzonitrile and the RuII- and IrI-catalyzed transfer hydrogenation of cyclohexanone in isopropanol. Finally, to enable access to asymmetric catalysts, chiral cycloiminophosphanes were prepared from l-menthone, as well as their P,N-κ2-RhIII and a P-κ1-RuII complexes.
- Rong, Mark K.,Holtrop, Flip,Bobylev, Eduard O.,Nieger, Martin,Ehlers, Andreas W.,Slootweg, J. Chris,Lammertsma, Koop
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- Dual nature of polyethylene glycol under microwave irradiation for the clean synthesis of oximes
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Polyethylene glycol (PEG-400 and PEG-600) is an efficient, inexpensive, and recyclable homogeneous medium and catalyst (dual nature) for the clean synthesis of oximes (and aldoximes) under microwave irradiation in the absence of acid and base catalysts. Both aliphatic and aromatic aldehydes/ketones give satisfactory results under microwave irradiation within a short time. Graphical abstract: [Figure not available: see fulltext.]
- Dutta, Papia,Dutta, Arup Kumar,Sarma, Parishmita,Borah, Ruli
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- Annulation of Oxime-Ether Tethered Donor–Acceptor Cyclopropanes
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Novel oxime-ether tethered cyclopropanes, when exposed to Yb(OTf)3 and heat, annulate to generate hydropyrrolo-oxazines products that can be taken to their respective pyrrolidines via hydrogenative N?O bond cleavage. The hydropyrrolo-oxazines are generated in a diastereoselective manner isolating the cis or trans product based on the temperature of the reaction. 20 examples of selective cis and trans hydropyrrolo-oxazines were generated in high yields by temperature control.
- Irwin, Lauren C.,Allen, Meredith A.,Vriesen, Matthew R.,Kerr, Michael A.
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- Reactivity of α-amino-peroxyl radicals and consequences for amine oxidation chemistry
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A comparative theoretical study is presented on the formation and fate of α-amino-peroxyl radicals, recently proposed as important intermediates in the aerobic oxidation of amines. After radical abstraction of the weakly bonded αH-atom in the amine substrate, the α-amino-alkyl radical reacts irreversibly with O2, forming the corresponding α-amino-peroxyl radical. HO2-elimination from various types of α-amino-peroxyl radicals (forming the corresponding imine) and the kinetically competing substrate H-abstraction (forming the α-amino-hydroperoxide) were computationally characterized. Polar solvents were found to reduce the HO 2-elimination barrier, but increase the barrier for H-abstraction. Depending on the reaction conditions (gas or liquid phase, amine concentration, nature of the solvent, and temperature), either of the two mechanisms is favored. The consequences for aerobic amine oxidation chemistry are discussed.
- Schuemperli, Martin T.,Hammond, Ceri,Hermans, Ive
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- Enolate-Based Regioselective Anti-Beckmann C-C Bond Cleavage of Ketones
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The Baeyer-Villiger or Beckmann rearrangements are established methods for the cleavage of ketone derivatives under acidic conditions, proceeding for unsymmetrical precursors selectively at the more substituted site. However, the fragmentation regioselectivity cannot be switched and fragmentation at the less-substituted terminus is so far not possible. We report here that the reaction of ketone enolates with commercial alkyl nitrites provides a direct and regioselective way of fragmenting ketones into esters and oximes or ω-hydroxyimino esters, respectively. A comprehensive study of the scope of this reaction with respect to ketone classes and alkyl nitrites is presented. Control over the site of cleavage is gained through regioselective enolate formation by various bases. Oxidation of kinetic enolates of unsymmetrical ketones leads to the otherwise unavailable "anti-Beckmann"cleavage at the less-substituted side chain, while cleavage of thermodynamic enolates of the same ketones represents an alternative to the Baeyer-Villiger oxidation or the Beckmann rearrangement under basic conditions. The method is suited for the transformation of natural products and enables access to orthogonally reactive dicarbonyl compounds.
- Jahn, Ullrich,Ma?ek, Tomá?
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- Metal-Free Synthesis of Adipic Acid via Organocatalytic Direct Oxidation of Cyclohexane under Ambient Temperature and Pressure
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A direct metal-free approach for the production of adipic acid from cyclohexane is reported. The use of N-hydroxyphthalimide (NHPI) as a catalyst in the presence of HNO3/TFA enables the direct oxidation of cyclohexane to yield adipic acid under ambient temperature and pressure via a simple procedure. This reaction proceeds through an initial oxidation of cyclohexane to cyclohexanone oxime and cyclohexanone followed by a second oxidation of these intermediates to adipic acid. NHPI plays a crucial role in both oxidation steps to achieve a high yield and selectivity for adipic acid.
- Matsumoto, Yohei,Kuriyama, Masami,Yamamoto, Kosuke,Nishida, Koyo,Onomura, Osamu
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- Novel Radical-Induced C-N Bond Formation
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Investigation of anomalous products from nitrate ester fragmentations have led to the discovery of a new route from alkyl halides to oximes.
- Fletcher, Rodney J.,Kizil, Murat,Murphy, John A.
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- One-pot conversion of cyclohexanol to ?-caprolactam using a multifunctional Na2WO4-acidic ionic liquid catalytic system
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Na2WO4-acidic ionic liquid was used as a simple, ecofriendly, recyclable and efficient catalytic system for the one-pot conversion of cyclohexanol to ?-caprolactam. The effect of the structure of the ionic liquid on the catalytic activity of this system was investigated, and the results revealed that sulfonic acid-functionalized ionic liquids with HSO4?as an anion gave the best results. The highly efficient performance of this catalyst system was attributed to the phase-transfer behavior of the cation of the ionic liquid, the improved coordination of the substrate to bisperoxotungstate during the oxidation reaction, and the stabilization of the intermediate formed during the Beckmann rearrangement.
- Wang, Hefang,Jia, Liyuan,Hu, Rongbin,Gao, Meidan,Wang, Yanji
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- Selenium-catalyzed deoxygenative reduction of aliphatic nitro compounds with carbon monoxide
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A reduction method of aliphatic nitro compounds to oximes using carbon monoxide was developed. When aliphatic nitro compounds were treated with carbon monoxide in the presence of a selenium catalyst, the corresponding oximes were formed in moderate to good yields.
- Nishiyama, Yutaka,Ikeda, Sadatatsu,Nishida, Hiroaki,Umeda, Rui
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- The influences of preparation methods on the structure and catalytic performance of single-wall carbon nanotubes supported palladium catalysts in nitrocyclohexane hydrogenation
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Single-wall carbon nanotubes (CNTs) supported palladium catalysts were prepared by different methods. The influences of different preparation methods on the structure and catalytic performance in nitrocyclohexane hydrogenation were investigated. The catalysts were characterized by nitrogen adsorption-desorption, XRD, TEM, hydrogen chemisorption and X-ray photoelectron spectroscopy. The results show that Pd/SWCNTs prepared by a water impregnation method provide a smaller particle size of palladium. The reduction conditions have great influence on the valence state of palladium on the support. A catalyst with smaller particle size, better dispersion and higher content of monovalent palladium exhibits better catalytic performance in nitrocyclohexane hydrogenation to cyclohexanone oxime. Pd/SWCNTs-2 prepared by a water impregnation method and reduced at 723 K has 96.4% selectivity when synthesizing cyclohexanone oxime with a 96.0% conversion from nitrocyclohexane under mild conditions of 0.3 MPa and 323 K.
- Liu, Sihua,Hao, Fang,Liu, Pingle,Luo, He'An
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- Photochemical and Chemical Reduction of Nitroalkenes Using Viologens as an Electron Phase-Transfer Catalyst
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An amphiphilic electron acceptor, i.e., N,N'-dioctyl-4,4'-bipyridinium, was used as an electron carrier between water-oil two phase, in which nitroalkenes in organic phase were readily reduced to the corresponding oximes and/or carbonyl compounds.
- Tomioka, Hideo,Ueda, Koichi,Ohi, Hirofumi,Izawa, Yasuji
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- Palladium supported catalysts for nitrocyclohexane hydrogenation to cyclohexanone oxime with high selectivity
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Different kinds of activated carbon- and carbon nanotube-supported palladium catalysts were investigated in the selective hydrogenation of nitrocyclohexane to cyclohexanone oxime under mild conditions. Carbon nanotube-supported palladium catalysts demonstrate better catalytic performance than activated carbon-supported palladium catalysts in general because of their mesoporous structures, which are favorable supports for the accessibility of the reactants to the active sites and the product desorption from the catalyst. Hydrogen chemisorption, transmission electron microscopy and X-ray photoelectron spectroscopy indicate that higher composition of Pd+ on the catalyst surface, larger palladium surface area, and better palladium dispersion contribute to an increase in the activity and selectivity toward cyclohexanone oxime. In addition, single-wall carbon nanotube-supported palladium catalysts give the best result of 97.7% conversion of nitrocyclohexane and 97.4% selectivity toward cyclohexanone oxime. On the basis of the results of GC-MS and the designed experiments, a possible reaction scheme was proposed. Brilliance in the performance: Carbon nanotube-supported palladium catalysts demonstrate better catalytic performance than activated carbon-supported palladium catalysts in general because of their mesoporous structures, which are favorable supports for the accessibility of the reactants to the active sites and the product desorption from the catalyst.
- Liu, Ping-Le,Zhang, Hai-Ke,Liu, Si-Hua,Yao, Zheng-Jie,Hao, Fang,Liao, Hong-Guang,You, Kui-Yi,Luo, He-An
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- Transfer hydrogenation of nitroarenes to arylamines catalysed by an oxygen-implanted MoS2 catalyst
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We present an efficient approach for chemoselective synthesis of various functionalized arylamines from nitroarenes over an oxygen-implanted MoS2 catalyst (O-MoS2). The HRTEM, XRD, XPS, Raman, EXAFS and NH3-TPD characterizations show the existence of MoIVOx structure and abundant coordinative unsaturated (CUS) Mo sites in the 2D-layer structure of O-MoS2. In the transfer hydrogenation of nitroarenes with hydrazine hydrate, the MoIVOx structure works as the catalytic active center. The N2H4 selectively decomposes to the active hydrogen species in polar electronic states (Hδ? and Hδ+), which show high chemoselectivity toward the nitro reduction over [Formula presented], [Formula presented], and [Formula presented] groups. The O-MoS2 catalyst can be recovered in a facile manner from the reaction mixture and recycled four times without any significant loss of activity.
- Zhang, Chaofeng,Zhang, Zhixin,Wang, Xu,Li, Mingrun,Lu, Jianmin,Si, Rui,Wang, Feng
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- Hydrogenation of nitrocyclohexane to cyclohexanone oxime over Pd/CNT catalyst under mild conditions
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The Pd/C, Pt/C, Ni/CNT and Pd/CNT catalysts were prepared by impregnation method and characterized by BET, XRD, TEM and H2 chemisorption. These catalysts were tested in the hydrogenation of nitrocyclohexane to cyclohexanone oxime. The results show that 5% Pd/CNT catalyst exhibits good performance, it gives nitrocyclohexane conversion of 97.6% and cyclohexanone oxime selectivity of 85.9% under mild conditions of 0.2 MPa and 323 K. The products include cyclohexanone oxime, cyclohexylamine, cyclohexanol and N- cyclohexylhydroxylamine. It has been found that higher temperature is in favor of the formation of cyclohexylamine, while the amount of cyclohexanol decreases with the increment of reaction temperature.
- Liao, Hong-Guang,Xiao, Yan-Juan,Zhang, Hai-Ke,Liu, Ping-Le,You, Kui-Yi,Wei, Chao,Luo, He'An
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- Synthesis and Photochemical Properties of 2,3;5,6-bis(cyclohexano)-BODIPY
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The boron-dipyrromethene (BODIPY) dye containing an annelated cyclohexyl rings at the 2,3 and 5,6-positions of pyrroles has been synthesized and characterized. Photochemical properties of the obtained compound have been investigated in different individua
- Kritskaya, Anna Yu.,Bumagina, Natalia A.,Antina, Elena V.,Ksenofontov, Alexander A.,Berezin, Mikhail B.,Semeikin, Alexander S.
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- Oxidation of amines over alumina based catalysts
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Amines were oxidized by molecular oxygen in the vapor phase at atmospheric pressure over alumina and silicotungstic acid/alumina catalysts. The study is focused on the influence of structure of amine and catalyst properties on the composition of the main reaction products and byproducts. Coating of γ-Al2O3 with silicotungstic acid or its semisalt can significantly enhance its catalytic activity in amine oxidation. The adsorption of amine on weak acidic sites of catalyst is essential for its oxidation to main reaction products. Cycloalkylamines are oxidized mainly to cyclic oximes (selectivity up to 64%) and Schiff bases of appropriate cycloalkanone and cycloalkylamine (selectivity up to 38%). Mainly nitriles (selectivity up to 55%) and appropriate Schiff bases (selectivity up to 54%) were observed in the oxidation products of primary alkylamines. Their molar ratio depends on the catalyst acidity and reaction conditions. 1,6-Hexanediamine is oxidized mainly to caprolactam (yield 48%) and other cyclic lactames and Schiff bases as well as to dinitrile (yield 13%).
- Rakottyay, Karol,Kaszonyi, Alexander,Vají?ek, Stanislav
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- Observations on the reaction of nitronate anions with oxalyl chloride: A new method for the preparation of geminal chloronitroso compounds
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A simple method for the preparation of geminal chloronitroso compounds from secondary nitro compounds via their derived nitronate anions is presented.
- Bou-Moreno, Rafael,Luengo-Arratta, Sandra,Motherwell, William B.
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- Reduction of conjugated nitroalkenes with zinc borohydride. A mild method for converting monosubstituted nitroalkenes to nitroalkanes and disubstituted ones to oximes
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Mono-β-substituted conjugated nitroalkenes are readily reduced by zinc borohydride in 1,2-dimethoxyethane to the corresponding nitroalkanes, whereas the disubstituted ones furnish the corresponding oximes in excellent yields.
- Ranu,Chakraborty
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- An efficient noble-metal-free supported copper catalyst for selective nitrocyclohexane hydrogenation to cyclohexanone oxime
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It was shown for the first time that cyclohexanone oxime (CHO) can be selectively produced by heterogeneous copper-catalyzed hydrogenative transformation of nitrocyclohexane (NC). The combination of Cu0 and Cu+ and their cooperative interaction with weakly acidic SiO2 supports elicited a significantly unique and selective catalysis in the hydrogenation of NC to CHO.
- Zhang, Qian-Qian,Dong, Jing,Liu, Yong-Mei,Cao, Yong,He, He-Yong,Wang, Yang-Dong
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- A convenient one-pot method of converting alcohols into oximes
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The one-pot conversion of primary and secondary alcohols into oximes is reported using chromium trioxide supported on alumina and hydroxylamine hydrochloride under solvent free condition. This oxidation-oxime formation reaction has been applied to a range of aliphatic and benzylic alcohols.
- Kiasat, Ali Reza,Kazemi, Foad,Nourbakhsh, Kazem
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- N-tert-Butyl-N-chlorocyanamide: A new reagent for the efficient preparation of gem-chloronitroso compounds
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A new reagent for the efficient preparation of gem-chloronitroso compounds has been developed. The reaction of ketoximes with N-tert-butyl-N- chlorocyanamide takes place instantaneously in carbon tetrachloride at room temperature with excellent yields under mild conditions.
- Kumar, Vinod,Kaushik
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- Preparation of cyclic prodiginines by mutasynthesis in pseudomonas putida kt2440
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Prodiginines are a group of naturally occurring pyrrole alkaloids produced by various microorganisms and known for their broad biological activities. The production of nature-inspired cyclic prodiginines was enabled by combining organic synthesis with a mutasynthesis approach based on the GRAS (generally recognized as safe) certified host strain Pseudomonas putida KT2440. The newly prepared prodiginines exerted antimicrobial effects against relevant alternative biotechnological microbial hosts whereas P. putida itself exhibited remarkable tolerance against all tested prodiginines, thus corroborating the bacterium’s exceptional suitability as a mutasynthesis host for the production of these cytotoxic secondary metabolites. Moreover, the produced cyclic prodiginines proved to be autophagy modulators in human breast cancer cells. One promising cyclic prodiginine derivative stood out, being twice as potent as prodigiosin, the most prominent member of the prodiginine family, and its synthetic derivative obatoclax mesylate.
- Klein, Andreas Sebastian,Brass, Hannah Ursula Clara,Klebl, David Paul,Classen, Thomas,Loeschcke, Anita,Drepper, Thomas,Sievers, Sonja,Jaeger, Karl-Erich,Pietruszka, J?rg
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- A mild system for synthesis of aldoximes and ketoximes in the presence of N-hydroxyphthalimide in aqueous system
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An efficient method for synthesis of oximes from aldehydes or ketones with N-hydroxyphthalimide or N-hydroxysuccinimide in water has been described. It is the first time to utilize NHPI as an oximation reagent to synthesize aldoximes and ketoximes from the corresponding organic carbonyl compounds without other reagents. The reaction tolerates various functional groups and affords the corresponding oximes in 76%–98% yields. The by-product phthalic acid can be recycled from the system. In addition, this method has been successfully applied to the synthesis of the precursor of some pharmacologically active amide molecules.
- Jiang, Xiaoying,Xu, Xiaohe,Lin, Yuyan,Yan, Yiyan,Li, Pingping,Bai, Renren,Xie, Yuanyuan
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- DYE SENSITIZED PHOTOOXYGENATION OF SUBSTITUTE OXIME CARBAMATES
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Solvolytic cleavage of oxime carbamates can be achieved by dye sensitized photooxygenation.A study with substituted oxime carbamates has revealed an unusual chemoselectivity of singlet oxygen towards carbon-nitrogen single bonds in preference over carbon-nitrogen double bonds in such compounds.
- Chawla, H. Mohindra,Hassner, Alfred
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- Site-specific catalytic activities to facilitate solvent-free aerobic oxidation of cyclohexylamine to cyclohexanone oxime over highly efficient Nb-modified SBA-15 catalysts
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The development of highly active and selective heterogeneous catalysts for efficient oxidation of cyclohexylamine to cyclohexanone oxime is a challenge associated with the highly sensitive nitrogen center of cyclohexylamine. In this work, dispersed Nb oxide supported on SBA-15 catalysts are disclosed to efficiently catalyze the selective oxidation of cyclohexylamine with high conversion (>75%) and selectivity (>84%) to cyclohexanone oxime by O2without any addition of solvent (TOF = 469.8 h?1, based on the molar amount of Nb sites). The role of the active-site structure identity in dictating the site-specific catalytic activities is probed with the help of different reaction and control conditions and multiple spectroscopy methods. Complementary to the experimental results, further poisoning tests (with KSCN or dehydroxylation reagents) and DFT computational studies clearly unveil that the surface exposed active centers toward activation of the reactants are quite different: the surface -OH groups can catch the NH2group from cyclohexylamine by forming a hydrogen bond and lead to a more facile cyclohexylamine oxidation to desired products, while the monomeric or oligomeric Nb sites with a highly distorted structure play a key role in the dissociation of O2molecules beneficial for insertion of active oxygen species into cyclohexylamine. These catalysts exhibit not only satisfactory recyclability for cyclohexylamine oxidation but also efficiently catalyze the aerobic oxidation of a wide range of amines under solvent-free conditions.
- Ding, Wei,Mao, Liqiu,Peng, Haoyu,Yin, Dulin,Zhong, Wenzhou
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- Highly effective synthesis of cyclohexanone oxime over a novel titanosilicate Ti-MWW
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Liquid-phase ammoximation of cyclohexanone proceeds extremely efficiently, selectively, and stablely over a novel titanosilicate Ti-MWW in a clean solvent of water, which would lead to a potential process more environmentally benign for synthesizing cyclo
- Song, Fen,Liu, Yueming,Wu, Haihong,He, Mingyuan,Wu, Peng,Tatsumi, Takashi
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- Reactivity of hydroxylamine ionic liquid salts in the direct synthesis of caprolactam from cyclohexanone under mild conditions
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The reactivity of several sulfobutyl hydrosulfate hydroxylamine ionic liquid salts in the direct synthesis of caprolactam from cyclohexanone under mild conditions was investigated. The results showed that the cyclohexanone conversion was mainly affected by cation species in the molecules of the hydroxylamine ionic liquid salts, and hydroxylamine N,N,N-trimethyl-N-sulfobutyl hydrosulfate salt was a better choice for the direct synthesis of caprolactam. The optimum reaction condition was at 80 °C for 4 h, and the suitable molar ratio of cyclohexanone: hydroxylamine ionic liquid salt: ZnCl2 was 2: 1:3. Under the optimal reaction conditions, cyclohexanone was almost completely converted into caprolactam, corresponding to 99.1% cyclohexanone conversion and 92.0% caprolactam selectivity. Furthermore, the reaction medium acetonitrile, and the ionic liquid which was combined in the hydroxylamine salt, can be recovered after the reaction, achieving an eco-friendly route for the direct synthesis of caprolactam.
- Li, Zhihui,Yang, Qiusheng,Gao, Liya,Xu, Yuanyuan,Zhang, Dongsheng,Wang, Shufang,Zhao, Xinqiang,Wang, Yanji
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- Selective hydrogenation of nitrocyclohexane to cyclohexanone oxime with H2 on decorated Pt nanoparticles
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A Pt catalyst has been designed to convert nitrocyclohexane into cyclohexanone oxime under mild hydrogenation conditions (4 bar of H2, 383 K, and solvent-free media). It has been found that the partial reduction of the nitro group to the oxime
- Serna, Pedro,Lopez-Haro,Calvino,Corma, Avelino
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- Synthesis, Characterization, and Catalytic Activities of Palladium Complexes with Phenylene-Bridged Bis(thione) Ligands
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The neutral phenylene-bridged bis(thione) compounds, 1,3-bis(3′-ethylimidazolyl-2′-thione)benzene (Betb), 1,3-bis(3′-butylimidazolyl-2′-thione)benzene (Bbtb), and 1,3-bis(3′-allylimidazolyl-2′-thione)benzene (Batb), have been synthesized and characterized. Reactions of palladium precursor PdCl2(CH3CN)2 with phenylene-bridged bis(thione) ligands in 1:2 ratio resulted in the formation of the complexes: PdCl2(L)2 (L = Betb, 3a; L = Bbtb, 3b; L = Batb, 3c, respectively). In contrast, treatment of the ligands with PdCl2(CH3CN)2 in 1:1 ratio gave cyclometalation palladium complexes Pd2+Cl(L-) (L = Betb-H, 4a; L = Bbtb-H, 4b; L = Batb-H, 4c) through the metal-induced C-H activation. Complexes 4a-c can also be obtained by the reaction of bis(thione) ligands and PdCl2 in 1:1 ratio. The reaction of 3a-c with additional PdCl2(CH3CN)2 also afforded complexes 4a-c. All ligands and palladium complexes were fully characterized by one-/two-dimensional NMR spectra, mass spectrometry, and infrared spectrometry. And the molecular structures of 3a-c, 4a, and 4c have been determined by the single-crystal X-ray diffraction method. Furthermore, the detailed spectroscopic properties and catalytic activities of the complexes for the reduction of nitro compounds were discussed in terms of the modification of the coordination ligands to the center metal.
- Jia, Wei-Guo,Gao, Li-Li,Wang, Zhi-Bao,Sun, Li-Ying,Han, Ying-Feng
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Read Online
- Mono-deoxygenation of nitroalkanes, nitrones, and heterocyclic N-oxides by hexamethyldisilane through 1,2-elimination: Concept of 'counterattack reagent'
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Transformation of secondary nitroalkanes to ketoximes was achieved in 40-73% yields by treatment of the corresponding nitronate anions with hexamethyldisilane. In this new mono-deoxygenation process, hexamethyldisilane acted as a 'counterattack reagent'. The conversion of nitrones to imines was also achieved in 82-88% yields by use of trimethylsilyllithium. Similarly, heterocyclic N-oxides were converted to the corresponding N-heterocycles in 73-86% yields. These deoxygenation processes presumably involve a 1,2-elimination.
- Hwu, Jih Ru,Tseng, Wen Nan,Patel, Himatkumar V.,Wong, Fong Fuh,Horng, Den-Nan,Liaw, Ben Ruey,Lung Ching, Lin
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Read Online
- Method for co-producing adipic acid and cyclohexanone-oxime from cyclohexane
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The invention relates to a method for co-producing adipic acid and cyclohexanone-oxime from cyclohexane. The method comprises the following steps: (1) carrying out oxidation nitration on cyclohexane and NOx to generate adipic acid, nitrocyclohexane, nitrogen oxides and a byproduct-A, and separating to obtain crude adipic acid and nitrocyclohexane; (2) carrying out catalytic hydrogenation on the obtained nitrocyclohexane and hydrogen to generate cyclohexanone-oxime and a small amount of cyclohexylamine, separating to obtain crude cyclohexanone-oxime and cyclohexylamine, and enabling cyclohexylamine to be directly used as a byproduct or to be continuously converted into cyclohexanone-oxime. and (3) partially oxidizing the cyclohexylamine obtained in the previous step with molecular oxygen to obtain an oxidation reaction product consisting of cyclohexanone-oxime, a byproduct B and possibly unconverted cyclohexylamine, and then separating the oxidation reaction product without separation, or firstly separating part or all of water in the oxidation reaction product, carrying out hydrogenation amination reaction under the action of a catalyst, or carrying out hydrogenation and amination reaction, or only carrying out hydrogenation reaction, and then separating to obtain the cyclohexanone-oxime. The method can realize high-selectivity co-production of adipic acid and cyclohexanone-oxime, and is short in process flow, low in equipment investment and low in material consumption, energy consumption and cost.
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Paragraph 0108-0109
(2021/06/13)
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- Tandem Synthesis of ?-Caprolactam from Cyclohexanone by an Acidified Metal-organic Framework
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Tandem synthesis of ?-caprolactam, one of the largest scaled commercial chemicals, is highly desired from the viewpoint of cost, energy, and environment. However, relevant studies have remained largely underexplored. By using a one-pot strategy, we encapsulated phosphotungstic acid (PTA) into a chromium terephthalate metal-organic framework (MOF), MIL-101, for the efficient tandem conversion of cyclohexanone to ?-caprolactam. The highly dispersed PTA in the MOF matrix showed a high yield of ?-caprolactam through a tandem oximation-Beckmann rearrangement reaction at 100 °C for 12 h. Moreover, MIL-101-PTA was recycled three times, with only a slight loss in their catalytic performance. To the best of our knowledge, this represents the first report using acidified MOF for a tandem oximation-Beckmann rearrangement reaction.
- Chen, Jingwen,Chen, Minda,Cruz, Andrew,Huang, Wenyu,Li, Xinle,Liu, Tianqing,Pei, Yuchen,Wu, Xun,Zhang, Biying
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p. 3084 - 3089
(2021/07/02)
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- Poly(N-vinylimidazole): A biocompatible and biodegradable functional polymer, metal-free, and highly recyclable heterogeneous catalyst for the mechanochemical synthesis of oximes
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The catalytic activity of poly(N-vinylimidazole), a biocompatible and biodegradable synthetic functional polymer, was investigated for the synthesis of oximes as an efficient, halogen-free, and reusable heterogeneous catalyst. The corresponding oximes were afforded in high to excellent yields at room temperature and in short times using the planetary ball mill technique. Some merits, such as the short reaction times and good yields for poorly active carbonyl compounds, and avoiding toxic, expensive, metal-containing catalysts, and hazardous and flammable solvents, can be mentioned for the current catalytic synthesis of the oximes. Furthermore, the heterogeneous organocatalyst could be easily separated after the reaction, and the regenerated catalyst was reused several times with no significant loss of its catalytic activity.
- Fahim, Hoda,Ghaffari Khaligh, Nader,Gorjian, Hayedeh
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p. 2007 - 2012
(2022/01/08)
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- Beckmann rearrangement of ketoximes promoted by cyanuric chloride and dimethyl sulfoxide under a mild condition
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Synthesis of amides via Beckmann rearrangement of ketoximes promoted by cyanuric chloride (TCT)/DMSO under mild conditions has been reported. Conditions of the Beckmann rearrangement, e.g., solvents, the ratios of TCT/DMSO, and the temperature, were investigated using diphenylmethanone oxime as a substrate. The optimized conditions were adopted to afford fourteen amides with yields ranging from 20% to 99%. A plausible mechanism involving an active dimethyl alkoxysulfonium intermediate was proposed according to the mass spectrometry analysis. To our best knowledge, this is the first case of study on Beckmann rearrangement of ketoximes promoted by TCT/DMSO under a mild condition to afford amides efficiently.
- Ma, Ruonan,Chen, Xueyuan,Xiao, Zhiyin,Natarajan, Mookan,Lu, Chunxin,Jiang, Xiujuan,Zhong, Wei,Liu, Xiaoming
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supporting information
(2021/01/06)
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- Analogues of the Herbicide, N-Hydroxy- N-isopropyloxamate, Inhibit Mycobacterium tuberculosis Ketol-Acid Reductoisomerase and Their Prodrugs Are Promising Anti-TB Drug Leads
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New drugs to treat tuberculosis (TB) are urgently needed to combat the increase in resistance observed among the current first-line and second-line treatments. Here, we propose ketol-acid reductoisomerase (KARI) as a target for anti-TB drug discovery. Twenty-two analogues of IpOHA, an inhibitor of plant KARI, were evaluated as antimycobacterial agents. The strongest inhibitor of Mycobacterium tuberculosis (Mt) KARI has a Ki value of 19.7 nM, fivefold more potent than IpOHA (Ki = 97.7 nM). This and four other potent analogues are slow- and tight-binding inhibitors of MtKARI. Three compounds were cocrystallized with Staphylococcus aureus KARI and yielded crystals that diffracted to 1.6-2.0 ? resolution. Prodrugs of these compounds possess antimycobacterial activity against H37Rv, a virulent strain of human TB, with the most active compound having an MIC90 of 2.32 ± 0.04 μM. This compound demonstrates a very favorable selectivity window and represents a highly promising lead as an anti-TB agent.
- Kandale, Ajit,Patel, Khushboo,Hussein, Waleed M.,Wun, Shun Jie,Zheng, Shan,Tan, Lendl,West, Nicholas P.,Schenk, Gerhard,Guddat, Luke W.,McGeary, Ross P.
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p. 1670 - 1684
(2021/02/27)
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- Preparation method of cyclohexanone oxime
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The invention relates to a preparation method of cyclohexanone oxime. The method comprises the following steps: carrying out partial oxidation reaction on cyclohexylamine and molecular oxygen under the action of a catalyst to obtain an oxidation reaction product consisting of cyclohexanone oxime, a byproduct and possibly unconverted cyclohexylamine; and then treating the oxidation reaction product in one of the following modes: (i) carrying out hydrogenation amination reaction with H2 and NH3 at the same time or carrying out hydrogenation and amination reaction in sequence under the action of a catalyst without separation or after part or all of water in the oxidation reaction product is separated, and then carrying out separation to obtain cyclohexanone oxime; and (ii) carrying out hydrogenation reaction with H2 under the action of a catalyst without separation or after part or all of water is separated out, and then carrying out separation to obtain the cyclohexanone oxime. The method disclosed by the invention has the characteristics of short process flow, small occupied area and investment, low material consumption and energy consumption (low cost), simplicity and convenience in operation, environment friendliness and the like.
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Paragraph 0067-0071
(2021/06/13)
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- Method for preparing cyclohexanone oxime by oxidizing cyclohexylamine
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The invention relates to an environmentally-friendly process for preparing cyclohexanone oxime by oxidizing cyclohexylamine, wherein cyclohexylamine as a raw material is oxidized with molecular oxygenby using a transition metal niobium modified mesoporous silicon-based molecular sieve as a catalyst at an operation temperature of 60-150 DEG C under an operation pressure of 0.1-2.0 MPa to prepare cyclohexanone oxime, wherein the catalyst is synthesized by modifying a transition metal niobium. The method has the advantages of high cyclohexylamine conversion rate, high cyclohexanone-oxime selectivity and environmental protection under a solvent-free condition.
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Paragraph 0011-0018
(2020/04/02)
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- A Fit-for-Purpose Synthesis of (R)-2-Methylazepane
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The preparation of new RSV inhibitors required an efficient synthesis of (R)-2-methylazepane ((R)-1) amenable to large-scale production to support preclinical studies. After consideration of different options, an efficient five-step synthesis relying on t
- Guizzetti, Sylvain,Michaut, Antoine,Federspiel, Guillaume,Eymard, Julien,Caron, Isabelle,Quatrevaux, Sabrina,Daras, Etienne,Jolly, Sandrine,Guillemont, Jér?me,Lan?ois, David
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supporting information
p. 729 - 733
(2020/01/31)
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- A Synergic Activity of Urea/Butyl Imidazolium Ionic Liquid Supported on UiO-66-NH2 Metal–Organic Framework for Synthesis of Oximes
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An efficient supported ionic liquid catalyst is designed for condensation reaction of aldehydes and ketones. The Zr-based metal–organic framework (MOF), UiO-66-NH2, was initially functionalized with N,N′-dibutyl imidazolium ionic liquid (UiO-66-NH2-ILBr–), and then urea was attached to the ionic liquid (IL) to form a task-specific IL. Bromide was exchanged with tetrafluoroborate and the catalyst exhibits excellent performance for the synthesis of oximes. The ionic liquid/urea coupling showed a synergistic effect on the efficiency of the reaction. The supported catalyst system was recycled simply by filtration and reused for five times without significant decrease in its activity. The catalyst was characterized with PXRD, FTIR, TGA, XPS, BET, FE-SEM, EDS, elemental mapping and elemental analysis (CHN). Graphic Abstract: MOF/IL/urea catalytic system was used for the synthesis of oximes[Figure not available: see fulltext.].
- Askari, Saeed,Jafarzadeh, Mohammad,Christensen, David Benjamin,Kegn?s, S?ren
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p. 3159 - 3173
(2020/04/21)
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- Photochemical Flow Oximation of Alkanes
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The nitrosation of several alkanes using tert-butyl nitrite has been performed in flow showing a remarkable reduction in the reaction time compared with batch processing. Due to the necessity for large excesses of the alkane component a continuous recycling process was devised for the preparation of larger quantities of material.
- Griffiths, Oliver M.,Ruggeri, Michele,Baxendale, Ian R.
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supporting information
p. 1907 - 1912
(2020/10/06)
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- Preparation method of cyclohexanone-oxime
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The invention relates to a preparation method of cyclohexanone-oxime, which mainly comprises the following steps: (1) oxidizing cyclohexane and molecular oxygen under the action of a solid catalyst, carrying out one-step reaction to generate KA oil, and performing separation to obtain the KA oil; (2) directly aminating the KA oil with ammonia and hydrogen under the action of a solid catalyst to generate cyclohexylamine and a small amount of byproduct-A, and performing separation to obtain cyclohexylamine; (3) carrying out partial oxidation on cyclohexylamine and molecular oxygen under the action of a solid catalyst to obtain an oxidation product mainly composed of cyclohexanone-oxime, a small amount of byproduct-B and cyclohexylamine which may not be completely converted; and (4) aminatingthe oxidation product, namely, directly carrying out amination reaction on the oxidation product obtained in the step (3), ammonia and hydrogen under the action of a solid catalyst without separation, converting the byproduct-B into cyclohexylamine, and performing separation to obtain cyclohexanone-oxime. The method is short in technological process, small in occupied area and investment, low incost and environmentally friendly.
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Paragraph 0037
(2020/06/05)
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- METHOD FOR PRODUCING C4-C15 LACTAMS
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The present invention relates to a process for preparing C4-C15 lactams, in which a C1-C10-alkyl nitrite is reacted with a C4-C15-cycloalkane and is illuminated with a light-emitting diode during the reaction. This forms a C4-C15-cyclohexanone oxime which is then converted further to a C4-C15 lactam; the C1-C10 alcohol formed is recycled into the preparation of the C1-C10-alkyl nitrite.
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Paragraph 0163; 0164
(2019/02/19)
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- Method for preparing cyclohexanone oxime by catalysis of transferring and hydrogenating of nitrocyclohexane
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The invention discloses a method for preparing cyclohexanone oxime by catalysis of transferring and hydrogenating of nitrocyclohexane. The method comprises the following steps: adding catalyst cupper-nickel-loaded activated carbon, nitrocyclohexane and an amine borane compound in a reactor according to the mass ratio of 0.1-0.4 to 1 to 2-20.8; reacting for 6 to 12 hours at 50 to 80 DEG C under stirring conditions to obtain a reaction liquid; filtering and separating the obtained reaction liquid to obtain the cyclohexanone oxime. According to the method, hydrogenation reaction of the nitrocyclohexane is catalyzed by taking a hydrogen storage material as a hydrogen donor; a preparation process can be completed through a common glass instrument without the equipment, such as a high-pressure reaction kettle, so that the cost of a reaction device is reduced, the operation of the reaction is simplified, and the safety of a reaction process is improved.
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Paragraph 0014-0022
(2019/01/17)
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- Method for preparing cyclohexanone-oxime by cyclohexylamine oxidation
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The invention discloses a method for preparing cyclohexanone-oxime by cyclohexylamine oxidation. According to the invention, titanium dioxide or supported titanium dioxide is used as a catalyst, and agas containing molecular oxygen is used as a green oxidant under the solvent-free condition to convert cyclohexylamine into cyclohexanone-oxime by one step; and by adjusting reaction temperature, reaction pressure, catalyst dosage and other conversion conditions, partial oxidation of cyclohexylamine is achieved to highly selectively obtain cyclohexanone-oxime. The reaction of cyclohexane oxidation for preparation of cyclohexanone and the reaction between cyclohexanone and hydroxylamine for preparation of cyclohexanone-oxime are bypassed, and various defects of the traditional process are avoided. According to the method of the invention, the reaction condition is mild, operation is simple, the process and equipment can be greatly simplified, product costs are reduced, and utilization rateof resources is increased. The method of the invention is an environmentally friendly green synthesis method.
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Paragraph 0052; 0053; 0054; 0055; 0056; 0057; 0058-0066
(2019/01/24)
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- SO2F2-Activated Efficient Beckmann Rearrangement of Ketoximes for Accessing Amides and Lactams
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A novel, mild and practical protocol for the efficient activation of the Beckmann rearrangement utilizing the readily available and economical sulfuryl fluoride (SO2F2 gas) has been developed. The substrate scope of the operationally simple methodology has been demonstrated by 37 examples with good to nearly quantitative isolated yields (over 90 % yield in most cases) in a short time, including B(OH)2, COOH, NH2, and OH substituted substrates. A tentative mechanism was proposed involving formation and elimination of key intermediate, sulfonyl ester.
- Zhang, Guofu,Zhao, Yiyong,Xuan, Lidi,Ding, Chengrong
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supporting information
p. 4911 - 4915
(2019/07/31)
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- Scope and mechanism of a true organocatalytic beckmann rearrangement with a boronic acid/perfluoropinacol system under ambient conditions
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Catalytic activation of hydroxyl functionalities is of great interest for the production of pharmaceuticals and commodity chemicals. Here, 2-alkoxycarbonyl- and 2-phenoxycarbonyl-phenylboronic acid were identified as efficient catalysts for the direct and chemoselective activation of oxime N-OH bonds in the Beckmann rearrangement. This classical organic reaction provides a unique approach to prepare functionalized amide products that may be difficult to access using traditional amide coupling between carboxylic acids and amines. Using only 5 mol % of boronic acid catalyst and perfluoropinacol as an additive in a polar solvent mixture, the operationally simple protocol features mild conditions, a broad substrate scope, and a high functional group tolerance. A wide variety of diaryl, aryl-alkyl, heteroaryl-alkyl, and dialkyl oximes react under ambient conditions to afford high yields of amide products. Free alcohols, amides, carboxyesters, and many other functionalities are compatible with the reaction conditions. Investigations of the catalytic cycle revealed a novel boron-induced oxime transesterification providing an acyl oxime intermediate involved in a fully catalytic nonself-propagating Beckmann rearrangement mechanism. The acyl oxime intermediate was prepared independently and was subjected to the reaction conditions. It was found to be self-sufficient; it reacts rapidly, unimolecularly without the need for free oxime. A series of control experiments and 18O labeling studies support a true catalytic pathway involving an ionic transition structure with an active and essential role for the boronyl moiety in both steps of transesterification and rearrangement. According to 11B NMR spectroscopic studies, the additive perfluoropinacol provides a transient, electrophilic boronic ester that is thought to serve as an internal Lewis acid to activate the ortho-carboxyester and accelerate the initial, rate-limiting step of transesterification between the precatalyst and the oxime substrate.
- Mo, Xiaobin,Morgan, Timothy D. R.,Ang, Hwee Ting,Hall, Dennis G.
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supporting information
p. 5264 - 5271
(2018/04/24)
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- Beckmann rearrangement of ketoxime catalyzed by N-methyl-imidazolium hydrosulfate
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Beckmann rearrangement of ketoxime catalyzed by acidic ionic liquid-N-methyl-imidazolium hydrosulfate was studied. Rearrangement of benzophenone oxime gave the desirable product with 45% yield at 90 ?C. When co-catalyst P2O5 was added, the yield could be improved to 91%. The catalyst could be reused three cycles with the same efficiency. Finally, reactions of other ketoximes were also investigated.
- Hu, Hongyu,Cai, Xuting,Xu, Zhuying,Yan, Xiaoyang,Zhao, Shengxian
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- Dichloroimidazolidinedione-Activated Beckmann Rearrangement of Ketoximes for Accessing Amides and Lactams
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A novel protocol for the activation of the Beckmann rearrangement utilizing the readily available and economical geminal dichloroimidazolidinediones (DCIDs) on a substoichiometric scale (10 mol %) has been developed. A unique self-propagating mechanism for the substoichiometric dichloroimidazolidinedione-activated transformation was proposed and validated. The substrate scope of the developed protocol has been demonstrated by 23 examples with good to excellent yields (mostly 90-98%) in a short time (mostly 10-30 min), including a substrate for synthesizing the monomer of nylon-12 and a complicated steroidal substrate on a preparative scale. This research not only unveils for the first time the synthetic potential of substoichiometric amounts of dichloroimidazolidinediones in promoting chemical transformation but also offers yet another important illustration of the self-propagating cycle in the context of the Beckmann rearrangement activated by a structurally novel organic promoter.
- Gao, Yu,Liu, Jingjing,Li, Zhenjiang,Guo, Tianfo,Xu, Songquan,Zhu, Hui,Wei, Fulan,Chen, Siming,Gebru, Hailemariam,Guo, Kai
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p. 2040 - 2049
(2018/02/23)
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- Preparation method of ketoxime
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The invention belongs to the technical field of ketoxime and specifically relates to a preparation method of ketoxime. The preparation method comprises the following steps: (1) sufficiently mixing ketone and hydroxylamine hydrochloride, adding absolute ethyl alcohol, and stirring till total dissolution to obtain mixed liquid 1; (2) adding imidazolyl anion functionalized ionic liquid into the mixedliquid 1, and heating till ethanol reflux, wherein reaction liquid is obtained after the reaction; (3) removing ethanol in the reaction liquid, adding deionized water and stirring to separate out solid, and performing suction filtration and washing to obtain white solid ketoxime. According to the preparation method provided by the invention, by taking the imidazolyl anion functionalized ionic liquid as a catalyst, a reaction between ketone and hydroxylamine hydrochloride can be efficiently catalyzed, and the preparation method has the advantages of mild reaction conditions, high product yieldand purity and the like.
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Paragraph 0038-0040
(2018/07/30)
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- Preparation method of cyclohexanone-oxime
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The invention relates to a preparation method of cyclohexanone-oxime. The method comprises the steps of firstly preparing N-cyclohexyl hexamethyleneimine through condensation reaction of cyclohexanone and cyclohexylamine as raw materials; and catalytically oxidizing the N-cyclohexyl hexamethyleneimine by employing molecular oxygen as an oxidizing agent under the action of a catalyst, and obtaining cyclohexanone-oxime and cyclohexanone at high yield, wherein the cyclohexanone circulates in the reaction process and is equivalent to a reaction medium; and efficient conversion of the N-cyclohexyl hexamethyleneimine into the cyclohexanone-oxime and the cyclohexanone is achieved through regulating the conversion conditions, such as the reaction temperature, the reaction pressure and the catalyst dosage. Multiple disadvantages of a traditional cyclohexanone-oxime preparation route are avoided, the reaction conditions are mild, the operation is simple, a product is high in yield, the utilization rate of resources is significantly improved and the preparation method is an environment-friendly synthesis method.
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Paragraph 0028; 0029; 0031; 0032; 0033; 0034-0044
(2017/09/18)
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- Direct preparation of oximes and Schiff bases by oxidation of primary benzylic or allylic alcohols in the presence of primary amines using Mn(III) complex of polysalicylaldehyde as an efficient and selective heterogeneous catalyst by molecular oxygen
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The present work introduced the new strategy for direct preparation of Schiff base as well as oxime compounds through oxidation of primary benzylic or allylic alcohols in the presence of amines by complexation of Mn(III) to a polymeric Schiff base ligand based on polysalicylaldehyde (PSA-Schiff base-Mn(III) complex). As a new environmentally benign protocol, manganese heterogeneous polymeric catalytic system demonstrated promising oxidation of alcohols in ethanol using molecular oxygen. PSA was synthesized through polycondensation reaction of 2-hydroxy-5-chloromethyl-benzaldehyde and then treated with 2-aminophenol to form polymeric ligand. Average molecular weight of PSA was studied by an analytical method as well as GPC analysis. Formation of the catalyst was characterized step by step by FTIR, UV–Vis, 1H NMR, TGA, CHN and EDX analyses. Loading amounts of metal ions as well as leaching amount of the catalysis were studied by ICP-OES instrument. The catalyst shows up to high yields for oxidation of primary and secondary primary benzylic or allylic alcohols to carbonyl compounds, especially direct imine formation in a mild, inexpensive and efficient method which can be successfully recovered from the reaction mixture and reused for several times without any remarkable reactivity loss. Effect of solvent, temperature, catalyst amount and oxygen donors along with some blank experiments to elucidation of catalyst activity was evaluated in this work. Also chemoselectivity behavior of the catalyst was investigated with some combinations.
- Kazemnejadi, Milad,Shakeri, Alireza,Mohammadi, Mohammad,Tabefam, Marzieh
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p. 1917 - 1933
(2017/08/15)
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- Novel process for synthesizing oxime through in-situ generated ammonia
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The invention discloses a novel process for synthesizing oxime through in-situ generated ammonia. The novel process is characterized in that ammonium salt and strong alkali and weak acid salt generate ammonia in situ, and then the ammonia reacts with ketone and hydrogen peroxide under catalysis of a titanium silicalite molecular sieve. The synthetic process has the advantages of simple oximation reaction, mild reaction conditions, few by-products, high product yield and environmentally friendliness. The synthesizing method is simple, an aftertreatment process is simple and convenient and has very strong operability and repeatability, and industrial production is promoted.
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Paragraph 0030; 0031; 0032; 0033
(2017/07/19)
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- ANTIVIRAL OXIME PHOSPHORAMIDE COMPOUNDS
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Compounds of Formula I: I and their pharmaceutically acceptable salts are useful for the inhibition of HIV reverse transcriptase. The compounds may also be useful for the prophylaxis or treatment of infection by HIV and in the prophylaxis, delay in the onset or progression, and treatment of AIDS. The compounds and their salts can be employed as ingredients in pharmaceutical compositions, optionally in combination with other antiviral agents, immunomodulators, antibiotics or vaccines.
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Page/Page column 30; 32
(2017/07/06)
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- Method used for synchronous production of cyclohexanone-oxime and acetone
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The invention provides a method used for synchronous production of cyclohexanone-oxime and acetone. According to the method, in the presence of oxygen, cyclohexanone, ammonia, and isopropanol are contacted with a titanium silicalite molecular sieve so as to obtain a mixture containing cyclohexanone-oxime and acetone. The method is capable of achieving relatively high cyclohexanone conversion rate and relatively high cyclohexanone-oxime selectivity, and producing side product acetone at the same time. The method is capable of realizing synchronous production of cyclohexanone-oxime and acetone; the raw materials are friendly to the environment; less environmental pollutant is generated; it is more beneficial for environment protection; and in addition, no solvent is used in the method, the raw materials are all used directly, preparation of solutions is not necessary, and device effective processing amount is not influenced.
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Paragraph 0041; 0042-0044; 0047; 0048; 0073-0075; 0079-0106
(2017/08/25)
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- Selective synthesis of primary anilines from cyclohexanone oximes by the concerted catalysis of a Mg-Al layered double hydroxide supported Pd catalyst
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Although the selective conversion of cyclohexanone oximes to primary anilines would be a good complement to the classical synthetic methods for primary anilines, which utilize arenes as the starting materials, there have been no general and efficient methods for the conversion of cyclohexanone oximes to primary anilines until now. In this study, we have successfully realized the efficient conversion of cyclohexanone oximes to primary anilines by utilizing a Mg-Al layered double hydroxide supported Pd catalyst (Pd(OH)x/LDH) under ligand-, additive-, and hydrogen-acceptor-free conditions. The substrate scope was very broad with respect to both cyclohexanone oximes and cyclohexenone oximes, which gave the corresponding primary anilines in high yields with high selectivities (17 examples, 75% to >99% yields). The reaction could be scaled up (gram-scale) with a reduced amount of the catalyst (0.2 mol %). Furthermore, the one-pot synthesis of primary anilines directly from cyclohexanones and hydroxylamine was also successful (five examples, 66-99% yields). The catalysis was intrinsically heterogeneous, and the catalyst could be reused for the conversion of cyclohexanone oxime to aniline at least five times with keeping its high catalytic performance. Kinetic studies and several control experiments showed that the high activity and selectivity of the present catalyst system were attributed to the concerted catalysis of the basic LDH support and the active Pd species on LDH. The present transformation of cyclohexanone oximes to primary anilines proceeds through a dehydration/dehydrogenation sequence, and herein the plausible reaction mechanism is proposed on the basis of several pieces of experimental evidence.
- Jin, Xiongjie,Koizumi, Yu,Yamaguchi, Kazuya,Nozaki, Kyoko,Mizuno, Noritaka
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p. 13821 - 13829
(2017/11/06)
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- On the Oxidation of Hydroxylamines with o -Iodoxybenzoic Acid (IBX)
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o -Iodoxybenzoic acid (IBX) is confirmed as a powerful tool for the oxidation of hydroxylamines. The synthetic route is demonstrated as efficient and user friendly, and is exploited on various carbohydrate-derived N,N-disubstituted hydroxylamines (cyclic, acyclic, and functionalized ones), affording the corresponding nitrones in good yields and regioselectivity. N-Monosubstituted hydroxylamines revealed an interesting divergent behavior depending on the reaction conditions. While IBX oxidation in dimethyl sulfoxide at 45 °C furnished oximes as reported, the oxidation in dichloromethane at room temperature afforded efficiently the unusual corresponding nitroso dimers.
- Parmeggiani, Camilla,Matassini, Camilla,Cardona, Francesca,Goti, Andrea
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p. 2890 - 2900
(2017/06/27)
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- M-CPBA mediated metal free, rapid oxidation of aliphatic amines to oximes
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An efficient, rapid oxidation of various aliphatic amines to oximes using m-CPBA as an oxidant in ethyl acetate is described. High conversion (100%) with >90% oxime selectivity is achieved at room temperature under catalyst-free conditions. Mild reaction conditions along with an easy work up procedure offer lower byproduct formation and high selectivity for oximes in good yield and purity.
- Patil, Vilas V.,Gayakwad, Eknath M.,Shankarling, Ganapati S.
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p. 781 - 786
(2016/02/18)
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- CATALYST, AND METHOD FOR PRODUCING OXIDATION PRODUCT
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A novel catalyst is provided which enables efficient production of an oxidation product by using an oxygen-induced oxidation reaction of an organic substrate. A novel method of using the catalyst enables efficient manufacturing of the oxidation product by oxidizing the organic substrate using oxygen. A catalyst used in the oxidation reaction of the organic substrate using oxygen contains compound (A), compounds (A) and (B), compounds (A) and (C), compounds (B) and (C), or compounds (A) and (B) and (C). A method for manufacturing the oxidation product using the catalyst involves bringing the organic substrate into contact with oxygen. Compound (A) is an inorganic peroxo acid, a salt of an inorganic peroxo acid, and/or N-halogenated succinimide, compound (B) is a nitroxide and/or a peroxide, and compound (C) is layered silicate.
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Paragraph 0135
(2016/12/22)
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- METHOD FOR PRODUCING OXIME
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Provided is a method for efficiently producing an oxime, which is a method for producing an oxime by oxidizing, an amine, the method comprising a first contact step and a second contact step, wherein the second contact step is performed by bringing an additional amine into contact with oxygen in the presence of at least a part of an oxidation product obtained in the first contact step.
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Paragraph 0092
(2016/04/09)
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- Cyclohexanone oxamidinating process for production of cyclohexanone oxime
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The invention relates to a method for preparing cyclohexanone-oxime from cyclohexanone ammoximation. The method comprises the following steps of: contacting reaction materials comprising hydrogen peroxide, cyclohexanone, a solvent and ammonia with titaniu
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Paragraph 0052-0067
(2016/10/09)
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- Method for decomposing ammonium chloride to prepare organic base hydrochloride and cyclohexanone-oxime synchronously
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The invention discloses a method for decomposing ammonium chloride to prepare organic base hydrochloride and cyclohexanone-oxime synchronously. The method comprises the steps of placing a titanium silicalite molecular sieve based catalyst and ammonium chl
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Paragraph 0036; 0083; 0084; 0085; 0086
(2016/12/01)
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- Method for preparing cyclohexanone-oxime from cyclohexanone through liquid-phase ammoximation
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The invention relates to a method for preparing cyclohexanone-oxime from cyclohexanone through liquid-phase ammoximation. The method includes the following steps that cyclohexanone, ammonia water, hydrogen peroxide, a catalyst, a surfactant, solvent and c
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Paragraph 0047
(2016/12/12)
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- Br?nsted acid catalyzed transoximation reaction: Synthesis of aldoximes and ketoximes without use of hydroxylamine salts
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The transoximation reaction enables the transfer of an oxime to a carbonyl compound and is catalyzed by transoximase in the pupae of the silkworm. Inspired by this bio-synthetic pathway, we achieved the transoximation of oximes to aldehydes and ketones catalyzed by a Br?nsted acid under mild conditions. Hydroxylamine salt, which necessitates a stoichiometric amount of base, was not required. NMR analysis clarified that this reaction proceeded through hydroxylamines generated by the successive hydrolysis of the oxime in situ. In addition, an environmentally benign method for catalytic transoximation was demonstrated in aqueous medium on a one hundred gram scale and the reaction filtrate containing the catalyst was recovered and reused over 10 times.
- Hyodo, Kengo,Togashi, Kosuke,Oishi, Naoki,Hasegawa, Genna,Uchida, Kingo
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supporting information
p. 5788 - 5793
(2016/11/06)
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