- Syntheses of ortho-hydroxymethylpyridinols and dioxaphosphorino[m,n-x]pyridines
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Dioxaphosphorino[m,n-x]pyridines compounds have been prepared by condensation of methyl dichlorophosphate with new ortho-hydroxymethylpyridinols.
- Leroy,Despres,Bigan,Blondeau
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Read Online
- Silica-supported vanadium-catalyzed N-oxidation of tertiary amines with aqueous hydrogen peroxide
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A recyclable silica supported vanadium 1 catalyzes the oxidation of tertiray amines to the corresponding N-oxides with 30% H2O 2 in high yield.
- Rout, Laxmidhar,Punniyamurthy, Tharmalingam
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- Trichloroacetonitrile-hydrogen peroxide: A simple and efficient system for the selective oxidation of tertiary and secondary amines
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A variety of tertiary and secondary amines were efficiently oxidized to their corresponding N-oxides and nitrones, respectively, using the trichloroacetonitrile-hydrogen peroxide system. The in situ generated trichloromethylperoxyimidic acid is the active reagent for the oxidation processes.
- Nikbakht, Fatemeh,Heydari, Akbar
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- A comparison of methods for N-oxidation of some 3-substituted pyridines
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The results from the N-oxidation of four 3-substituted pyridines using five different reagents are reported. The best yields are obtained with m-chloroperoxybenzoic acid.
- Bremner, David H.,Sturrock, Keith R.,Wishart, Grant,Mitchell, Stewart R.,Nicoll, Stuart M.,Jones, Gareth
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- Raman spectra of 3-methyl-4-nitropyridine-N-oxide single crystal
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A Raman study of 3-methyl-4-nitropyridine-N-oxide single crystal (3M4NPO) has been performed at 78 K in the range 10-3500 cm-1.The symmetry analysis of the vibrational modes of 3M4NPO is given.The assignments are presented for internal and external modes.The results of the Raman spectra exhibit the spectroscopic proofs of hydrogen bonds in the crystal.
- Zhang, Delong,Lan, Guoxiang,Hu, Shifen,Wang, Huafu,Zheng, Jimin
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- Organic salts of polyoxometalates: Novel and efficient catalysts for the synthesis of pyridine n-oxide derivatives
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Catalytic N-oxidation of pyridine derivatives to related N-oxides were performed in the peresence of three organic salts of polyoxometalates including two heteropolyanion (THA)7.7H6.3[NaP5W 30O110], 1, and (THPA)7.5 H 6.5[NaP5W30O110], 2, and one isopolyanion [TBA]2[W6O19] (3) with W as central metal atom. Catalyst (3) showed the best catalytic activity. The highly selective oxidation gave good to excellent yields of the related N-oxides along with decarboxylation at 2-position of pyridine ring. The effect of some operative variables, such as temperature, various solvents, and the reaction time was studied. The reaction conditions were optimized. Copyright Taylor & Francis Group, LLC.
- Tavakoli-Hoseini, Niloofar,Bamoharram, Fatemeh F.,Heravi, Majid M.
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- Metal-Free, Phosphonium Salt-Mediated Sulfoximination of Azine N-Oxides: Approach for the Synthesis of N-Azine Sulfoximines
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Herein, we report a simple and metal-free method for the synthesis of N-azine sulfoximines by the nucleophilic substitution of azine N-oxides with NH-sulfoximines. The present method works at room temperature with wide functional group compatibility and gives several unprecedented N-azine sulfoximines. The reaction conditions were also found suitable with enantiopure substrates and furnished products without any racemization. It also finds an application in the sulfoximination of azine-based functional molecules such as 2,2′-bipyridine, 1,10-phenanthroline, and quinine.
- Aithagani, Sravan Kumar,Kumar, Mukesh,Yadav, Mahipal,Vishwakarma, Ram A.,Singh, Parvinder Pal
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- Uniting Amide Synthesis and Activation by PIII/PV-Catalyzed Serial Condensation: Three-Component Assembly of 2-Amidopyridines
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An organophosphorus (PIII/PVredox) catalyzed method for the three-component condensation of amines, carboxylic acids, and pyridineN-oxides to generate 2-amidopyridines via serial dehydration is reported. Whereas amide synthesis and functionalization usually occur under divergent reaction conditions, here a phosphetane catalyst (together with a mild bromenium oxidant and terminal hydrosilane reductant) is shown to drive both steps chemoselectively in an auto-tandem catalytic cascade. The ability to both prepare and functionalize amides under the action of a single organocatalytic reactive intermediate enables new possibilities for the efficient and modular preparation of medicinal targets.
- Lipshultz, Jeffrey M.,Radosevich, Alexander T.
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supporting information
p. 14487 - 14494
(2021/09/18)
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- Visible-Light-Induced Decarboxylative Acylation of Pyridine N-Oxides with α-Oxocarboxylic Acids Using Fluorescein Dimethylammonium as a Photocatalyst
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Herein, the development of a visible-light-induced catalytic system to achieve the decarboxylative acylation of pyridine N-oxides with α-oxocarboxylic acids, at room temperature and using the organic dye fluorescein dimethylammonium as a new type of photocatalyst, is reported. A series of 2-arylacylpyridine N-oxides were selectively synthesized in moderate to good yields by controlling the polarity of the reaction solvent. The developed strategy was successfully applied in the synthesis of an important intermediate of the drug, acrivastine, on a gram scale. Notably, this is the first time that fluorescein dimethylammonium has been used to catalyze the Minisci-type C?H decarboxylative acylation reaction. The mechanism of decarboxylative acylation was studied by capturing adducts of acyl radicals and 1,1-diphenylethylene to confirm a radical mechanism. The disclosed catalytic system provides a green synthetic strategy for decarboxylative acylation without the use of additional oxidants or metal catalysts. (Figure presented.).
- Hou, Chuanfu,Sun, Shouneng,Liu, Ziqi,Zhang, Hui,Liu, Yue,An, Qi,Zhao, Jian,Ma, Junjie,Sun, Zhizhong,Chu, Wenyi
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supporting information
p. 2806 - 2812
(2021/04/15)
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- The M?CPbA?NH3(G) system: A safe and scalable alternative for the manufacture of (substituted) pyridine and quinoline N?oxides?
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An improved, safe, and scalable isolation process for (substituted) pyridine and quinoline N-oxides in quantitative yields along with high purities using the m-CPBA?NH3(g) system is described. The safety was assessed by reaction calorimetry and differential scanning calorimetry studies for possible hazards during the conversion and isolation steps. Careful interpretation of the data substantiated the safety and scalability. The process flow is simplified to meet the industrial requirements of safety, cost-effectiveness, and utility minimization. The reaction was safely demonstrated at a 2.5 kg scale.
- Palav, Amey,Misal, Balu,Ernolla, Anilkumar,Parab, Vinod,Waske, Prashant,Khandekar, Dileep,Chaudhary, Vinay,Chaturbhuj, Ganesh
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supporting information
p. 244 - 251
(2019/03/17)
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- Strategic Approach on N-Oxides in Gold Catalysis – A Case Study
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An extensive kinetic study of selected key reactions of (oxidative) gold catalysis concentrates on the decrease of the catalytic activity due to inhibition of the gold(I) catalyst caused by pyridine derivatives that are obtained as by-products if N-oxides are applied as oxygen donors. The choice of the examined pyridine derivatives and their corresponding N-oxides has been made regardless of their commercial availability; particular attention has been paid to the practical benefit which up to now has been neglected in most of the reaction screenings. The test reactions were monitored by GC and 1H NMR spectroscopy. The received reaction constants provide information concerning a correlation between the electronic structure of the heterocycle and the catalytic activity. Based on the collected kinetic data, it was possible to develop a basic set of three N-oxides which have to be taken into account in further oxidative gold(I)-catalyzed reactions. (Figure presented.).
- Schie?l, Jasmin,Stein, Philipp M.,Stirn, Judith,Emler, Kirsten,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
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supporting information
p. 725 - 738
(2018/10/20)
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- A 3 - pyridine formaldehyde synthetic method
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The present invention relates to machine the chemical field, in particular to a 3 - pyridine formaldehyde synthetic method, comprises the following steps: 1, to 3 - methyl pyridine as raw materials, under acidic conditions, through the oxidation reaction
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Paragraph 0032-0033; 0037-0038; 0042-004.
(2019/05/28)
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- A methyl pyridine nitrogen oxide oxidizing synthesis method
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The invention discloses an oxosynthesis method of methylpyridine-1-oxide, comprising two steps of preparation of a catalyst and oxidation reaction, wherein the preparation of the catalyst comprises the steps of after cleaning, high temperature boiling, drying and cooling pretreatment of activated carbon, adding into a phosphotungstic acid solution, stirring till complete soaking, and after ultrasonic treatment, evaporating to remove a solvent to obtain a phosphotungstic acid supported on active carbon catalyst; the oxidation reaction comprises the steps of mixing methylpyridine with the phosphotungstic acid supported on active carbon catalyst, stirring, adding hydrogen peroxide for reaction, and separating the phosphotungstic acid supported on active carbon catalyst to obtain methylpyridine-1-oxide filtrate being a methylpyridine-1-oxide crude product, and distilling under reduced pressure to obtain the product. When the method is used for preparing the catalyst, a carrier is cheap and convenient, a preparation process is simple, the catalyst in the oxidation reaction is less in use level, convenient to recycle, resuable and low in cost, product yield is up to 97%, product purity is up to 98% and productivity is more than 98%.
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Paragraph 0049; 0050; 0051
(2018/05/16)
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- Method for preparing 3-picoline-N-oxide
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A method for preparing 3-picoline-N-oxide belongs to the synthesis technology of pesticide/pharmaceutical chemical intermediates. 3-methylpyridine and hydrogen peroxide are quickly mixed in a micro-mixer, the obtained mixture is oxidized in a micro-reacto
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Paragraph 0032; 0035; 0038; 0041-0047; 0050; 0051
(2018/07/07)
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- A mild and efficient H2O2 oxygenation of N-heteroaromatic compounds to the amine N-oxides and KI deoxygenation back to the tertiary amine with hexaphenyloxodiphosphonium triflate
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A mild and efficient method for the oxidation of N-heteroaromatic compounds to the corresponding N-oxides using H2O2 in the presence of hexaphenyloxodiphosphnium triflate (Hendrickson reagent) in EtOH at room temperature was reported. This methodology presented relatively fast and selective reactions to afford the N-oxides in good yields. The reverse reactions, deoxygenation reactions, were also carried out under the same reaction conditions by KI to produce the tertiary amines.
- Khodaei, Mohammad Mehdi,Alizadeh, Abdolhamid,Hezarkhani, Hadis Afshar
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p. 1843 - 1849
(2018/07/06)
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- Visible Light-Mediated Decarboxylative Alkylation of Pharmaceutically Relevant Heterocycles
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A net redox-neutral method for the decarboxylative alkylation of heteroarenes using photoredox catalysis is reported. Additionally, this method features the use of simple, commercially available carboxylic acid derivatives as alkylating agents, enabling the facile alkylation of a variety of biologically relevant heterocyclic scaffolds under mild conditions.
- Sun, Alexandra C.,McClain, Edward J.,Beatty, Joel W.,Stephenson, Corey R. J.
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supporting information
p. 3487 - 3490
(2018/06/26)
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- Catalytic synthesis method for 3-methyl-pyridin-N-oxide
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The invention provides a catalytic synthesis method for 3-methyl-pyridin-N-oxide. The method comprises the steps of adding 3-methylpyridine, a composite metallic oxide catalyst Ni0.2Mn0.3Ge0.1O6 and acetic acid into a reaction vessel, carrying out stirrin
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Paragraph 0017-0046
(2017/07/20)
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- A 3 - substituted - 2 - cyano pyridine compound of preparation method
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The present invention discloses a 3-substituted-2-cyanopyridine compound preparation method, which comprises: (1) mixing a solution of 3-substituted pyridine-N-oxide represented by a formula I and an acyl halide compound, and reacting to obtain a reactant; and (2) mixing the reactant I and a cyanide aqueous solution to obtain the 3-substituted-2-cyanopyridine compound represented by a formula II, wherein R is selected from methyl, halogen, hydroxy, cyano, 2-hydroxyethyl, methoxy, and 1-cyanomethyl.
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Paragraph 0089-0091
(2017/09/02)
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- Pyridine synthesis of heterocyclic nitrogen oxide
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The invention provides a synthesis method of pyridine heterocycle oxynitrides, which comprises the following steps: mixing a catalyst {Mo132}, pyridine compounds and 30% hydrogen peroxide in a mole ratio of 1:143:714 in a mixed solvent composed of ethanol and water in a volume ratio of 2:3 at room temperature to react for 6-24 hours, extracting with a dichloromethane organic solvent, and purifying by distilling with an organic phase dichloromethane to obtain the pyridine heterocycle oxynitride product. Compared with the past systems, the catalytic system can complete the catalytic oxidation of the pyridine compounds and quinoline compounds at room temperature within a short time, is reusable and has high yield.
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Paragraph 0018; 0019
(2017/08/25)
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- A pyridine nitrogen oxide high-efficient, multi-phase catalytic preparation method
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The invention discloses a high efficient heterogeneous catalytic preparation method of pyridine oxynitride. In the provided preparation method, mono-substituted or poly-substituted pyridines or pyridine derivatives are taken as the primary raw materials, titanium dioxide loaded on tungsten (WO3/TiO2) is taken as the catalyst, hydrogen peroxide is taken as the oxidizing agent, and reactions are carried out in a water solution at a room temperature so as to obtain the target product. Compared with the prior art, the preparation method has the following advantages: (1) the provided oxidation method, no acetic acid is used, and thus the requirements on equipment are greatly reduced; (2) a heterogeneous catalytic method is adopted to prepare pyridine oxynitride, the catalyst can be separated from the reaction system through simple filtration or centrifugation, and the operation is convenient; (3) titanium dioxide loaded on tungsten is taken as the catalyst, pyridine oxynitride is prepared by one step in a water solution at a room temperature, the reaction conditions are mild, and the pollution to the environment is little.
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Paragraph 0125; 0129; 0130; 0131
(2017/08/25)
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- 2,2′-Homocoupled Azine N,N′-Dioxides or Azine N-Oxides: CDC- or SNAr-Controlled Chemoselectivity
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An unprecedented Cu(OAc)2- and LiOtBu-mediated homocoupling of azine N-oxides to yield 2,2′-azine N,N′-dioxides is reported. This is the first instance in which copper has been used to catalyze the homodimerization reaction, especially of 2-phenylpyridine N-oxides. In the absence of catalytic copper, the reaction follows an alternative pathway, and instead of dioxides it yields 2,2′-azine N-monoxides. This latter protocol works efficiently with a range of N-heterocyclic oxides of pyridine, 2-phenylpyridine, quinoline and N-aryl-1,2,3-triazole. It is scalable, offers high regioselectivity and gives the products in moderate to high yields. The observed chemoselectivity between the copper-assisted and copper-free protocols is routed through oxidative cross-dehydrogenative coupling (CDC) and nucleophilic aromatic substitution of hydrogen (SNAr) pathways, respectively.
- Jha, Abadh Kishor,Jain, Nidhi
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p. 4765 - 4772
(2017/09/07)
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- Synthetic method of 2-amino-5-methyl pyridine
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The invention provides a synthetic method of 2-amino-5-methyl pyridine and relates to the field of research and development of chemical synthesis of drugs. The synthetic method comprises the following steps: adding methyl groups to pyridine to prepare 5-methyl pyridine; preparing N-oxidative methyl pyridine by 5-methyl pyridine; preparing 2-nitro-5-methyl nitrogen-oxidative pyridine by nitrogen-oxidative pyridine; and preparing the 2-amino-5-methyl pyridine by the 2-nitro-5-methyl nitrogen-oxidative pyridine. The synthetic method provided by the invention has the advantages of high product yield and purity, low in production cost and good in environment-friendly effect.
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Paragraph 0025; 0028; 0034; 0038; 0040
(2017/11/16)
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- Renewable waste rice husk grafted oxo-vanadium catalyst for oxidation of tertiary amines to N-oxides
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Low cost renewable waste rice husks (RH) have been used as a support for grafting of an oxo-vanadium Schiff base via covalent attachment for the oxidation of tertiary amines to N-oxide. The synthesis of the desired RH grafted oxo-vanadium complex involves prior functionalization of the RH support with amino-propyltrimethoxysilane (APTMS) followed by its reaction with salicylaldehyde to get an RH-functionalized Schiff base which subsequently reacted with vanadyl sulphate to get the targeted oxo-vanadium catalyst. The synthesized catalyst was found to be an efficient heterogeneous catalyst and afforded an excellent yield of corresponding N-oxides via oxidation of tertiary amines with hydrogen peroxide as an oxidant. Furthermore, the synthesized catalyst was found to be quite stable and showed consistent activity for five runs without any loss in activity.
- Panwar, Vineeta,Bansal, Ankushi,Ray, Siddharth S.,Jain, Suman L.
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p. 71550 - 71556
(2016/08/05)
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- Solvent- and halide-free synthesis of pyridine-2-yl substituted ureas through facile C-H functionalization of pyridine: N -oxides
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A novel solvent- and halide-free atom-economical synthesis of practically useful pyridine-2-yl substituted ureas utilizes easily accessible or commercially available pyridine N-oxides (PyO) and dialkylcyanamides. The observed C-H functionalization of PyO is suitable for the good-to-high yielding synthesis of a wide range of pyridine-2-yl substituted ureas featuring electron donating and electron withdrawing, sensitive, or even fugitive functional groups at any position of the pyridine ring (63-92%; 19 examples). In the cases of 3-substituted PyO, the C-H functionalization occurs regioselectively providing a route for facile generation of ureas bearing a 5-substituted pyridine-2-yl moiety.
- Rassadin, Valentin A.,Zimin, Dmitry P.,Raskil'dina, Gulnara Z.,Ivanov, Alexander Yu.,Boyarskiy, Vadim P.,Zlotskii, Semen S.,Kukushkin, Vadim Yu.
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supporting information
p. 6630 - 6636
(2018/03/01)
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- A lipase-glucose oxidase system for the efficient oxidation of: N -heteroaromatic compounds and tertiary amines
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In this work, a lipase-glucose oxidase system has been designed and proven to be an efficient system for the oxidation of N-heteroaromatic compounds and tertiary amines. This dual-enzyme system not only displays environmental friendliness, but also demonstrates its huge potential in industrial applications.
- Yang, Fengjuan,Zhang, Xiaowen,Li, Fengxi,Wang, Zhi,Wang, Lei
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supporting information
p. 3518 - 3521
(2016/07/06)
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- Base free regioselective synthesis of α-triazolylazine derivatives
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A regioselective α-heteroarylation followed by deoxygenation towards the synthesis of variety of azine triazole from simple azine N-oxides derivatives and N-tosyl-1,2,3-triazoles has been described. The reaction is metal free and base free with shorter reaction time, high yields and a broad substrate scope.
- Harisha, Mysore Bhyrappa,Nagaraj, Muthupandi,Muthusubramanian, Shanmugam,Bhuvanesh, Nattamai
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p. 58118 - 58124
(2016/07/06)
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- The microwave-assisted ortho-alkylation of azine N-oxides with N-tosylhydrazones catalyzed by copper(i) iodide
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A copper catalyzed regioselective cross-coupling of N-tosylhydrazones with azine N-oxides to yield ortho-alkylated products in moderate to good yields is reported. The reaction is facilitated by microwave, takes place without any ligand, and uses inexpensive copper(i) iodide as the catalyst.
- Jha, Abadh Kishor,Jain, Nidhi
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supporting information
p. 1831 - 1834
(2016/02/05)
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- Facile Immobilization of a Lewis Acid Polyoxometalate onto Layered Double Hydroxides for Highly Efficient N-Oxidation of Pyridine-Based Derivatives and Denitrogenation
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N-Oxides are a class of highly important compounds that are used widely as synthetic intermediates. In this paper, we demonstrate for the first time the use of a polyoxometalate-based composite material as a highly efficient heterogeneous catalyst for the N-oxidation of pyridines and its derivatives in the presence of H2O2 at room temperature. The composite was prepared by the intercalation of the [La(PW11O39)2]11- anion into a layered double hydroxide (LDH) modified with tris(hydroxymethyl)aminomethane (Tris). Additionally, the Tris-LDH-La(PW11)2-based catalyst has been employed for the denitrogenation of a model oil mixture in the presence of 1-butyl-3-methylimidazolium tetrafluoroborate and H2O2. Denitrogenation can be achieved in 40 min at 75 C. Finally, the heterogeneous catalyst can be recovered easily and reused at least 10 times without a measurable decrease of the catalytic activity and disintegration of the Tris-LDH-La(PW11)2 structure. Between the sheets: We demonstrate for the first time the use of a polyoxometalate-based composite material as a highly efficient heterogeneous catalyst for the N-oxidation of pyridines and its derivatives in the presence of H2O2 at room temperature. The composite is prepared by the intercalation of the [La(PW11O39)2]11- anion into a layered double hydroxide modified with tris(hydroxymethyl)aminomethane.
- Liu, Kai,Yao, Zhixiao,Miras, Haralampos N.,Song, Yu-Fei
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p. 3903 - 3910
(2016/01/26)
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- Catalytic system for pyridine oxidation to N-oxides under mild conditions based on polyoxomolybdate
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A reusable and effective catalytic system has been developed for oxidation of pyridines catalyzed by Keplerate polyoxomolybdate ({Mo132}) at room temperature. Pyridine compounds could be oxidized in high yields under mild conditions.
- Yang, Chunxia,Zhao, Wei,Cheng, Zhiguo,Luo, Baomin,Bi, Dongqin
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p. 36809 - 36812
(2015/05/05)
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- HETEROCYCLIC COMPOUNDS AS PROTEIN KINASE INHIBITORS
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The present invention provides a heterocyclic compound of formula (I), a pharmaceutically acceptable salt thereof, a prodrug thereof or a hydrate thereof, wherein A, A′ B, D, R1, R2 and R3 are as defined herein, a pharmaceutical composition comprising a compound of formula (I) as an active ingredient, methods of production, and methods of use thereof. Particularly, the present invention provides a compound of formula (I) useful for treating or preventing a disease, condition or disorder associated with protein kinases, preferably Janus Kinase family.
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Paragraph 0429
(2014/06/23)
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- 2,2,2-Trifluoroacetophenone as an organocatalyst for the oxidation of tertiary amines and azines to N-oxides
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A cheap, mild and environmentally friendly oxidation of tertiary amines and azines to the corresponding Noxides is reported by using polyfluoroalkyl ketones as efficient organocatalysts. 2,2,2-Trifluoroacetophenone was identified as the optimum catalyst for the oxidation of aliphatic tertiary amines and azines. This oxidation is chemoselective and proceeds in high-to-quantitative yields utilizing 10 mol% of the catalyst and H2O2 as the oxidant.
- Limnios, Dimitris,Kokotos, Christoforos G.
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supporting information
p. 559 - 563
(2014/04/03)
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- Design, synthesis and antiproliferative activity evaluation of new 5-azaisoindigo derivatives
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New 5-azaisoindigo derivatives were synthesized with two key intermediates 5-azaoxindole (7) and substituted indole-2,3-dione (10) in this paper. Intermediate 7 was prepared from 3-methylpyridine (1) through 6 steps containing oxidation reaction and so on. Intermediate 10 was obtained by a convenient Sandmeyer's method. The target compounds 5-azaisoindigo derivatives 11a-f were obtained by condensation of these two intermediates 7 and 10 in acidic condition. All target compounds were evaluated for their antiproliferative activity against seven cell lines by SRB assay. Compounds 11e and 11f showed significant antiproliferative activity against K562 cells (IC50: 8.9 μM and 13.6 μM, respectively).
- Zhao, Ping,Yan, Yun,Li, Yanzhong,Zhang, Aiying,Zhan, Xiaoping,Liu, Zenglu,Mao, Zhenmin,Chen, Shaoxiong,Wang, Liqun
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p. 1923 - 1932
(2014/08/18)
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- Green and reusable synthetic procedure for pyridine N-oxides catalyzed by a lacunary polyoxometalate
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A lacunary Keggin polyoxometalate of K8[BW11O39H] · 13H2O was used as an effective and reusable catalyst for pyridine oxidation. Good yields of pyridine N-oxides were obtained in this catalytic system with hydrogen peroxide in water under mild conditions. Taylor and Francis Group, LLC.
- Zhao, Wei,Wang, Xing,Yang, Chunxia
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p. 150 - 160
(2013/11/06)
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- Oxidation of alcohols and pyridines by a water-soluble polyoxometalate with hydrogen peroxide
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A water-soluble catalyst based on a silicotungstate polyoxometalate, K 8[β-SiW11O39] · 14H2O, was developed for the oxidation of pyridines and alcohols with hydrogen peroxide. The reactions were carried out in water, and good yields of the corresponding heterocyclic N-oxides and ketones were obtained under relatively mild conditions. The catalyst could be easily recovered by extraction with ethyl acetate and reused several times. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Zhang, Zhenxin,Zhu, Qianqian,Ding, Yong
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supporting information
p. 1211 - 1218
(2013/03/29)
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- A green catalytic procedure for oxidation of pyridines catalyzed by a lacunary polyoxometalate in water at room temperature
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A green and reusable catalytic procedure for oxidation of pyridines to N-oxides was developed. High yields of heterocyclic N-oxides were obtained when catalyzed by Δ-Na8HPW9O34 in water at room temperature. The catalyst used in the system could be recovered and reused several times without obvious loss of activity.
- Zhao, Wei,Yang, Chunxia
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supporting information
p. 1867 - 1870
(2013/10/08)
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- HETEROCYCLIC COMPOUNDS AS PROTEIN KINASE INHIBITORS
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The present invention provides a heterocyclic compound of formula (I), a pharmaceutically acceptable salt thereof, a prodrug thereof or a hydrate thereof, wherein A, A' B, D, R1, R2 and R3 are as defined herein, a pharmaceutical composition comprising a compound of formula (I) as an active ingredient, methods of production, and methods of use thereof. Particularly, the present invention provides a compound of formula (I) useful for treating or preventing a disease, condition or disorder associated with protein kinases, preferably Janus Kinase family.
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Page/Page column 71
(2012/12/13)
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- Mild and recyclable catalytic oxidation of pyridines to N-oxides with H2O2 in water mediated by a vanadium-substituted polyoxometalate
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A vanadium-substituted polyoxometalate, K6[PW9V 3O40]·4H2O, was used as a recyclable and effective catalyst for the oxidation of pyridines. The reactions were successfully conducted in water under mild conditions. The catalyst could be easily recovered and reused.
- Ding, Yong,Zhao, Wei,Song, Wenfeng,Zhang, Zhenxin,Ma, Baochun
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supporting information; experimental part
p. 1486 - 1489
(2011/08/03)
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- Oxidation of organic compounds by sulfonated porous carbon and hydrogen peroxide
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The oxidation of organic compounds by sulfonated porous carbon and H 2O2 was studied at room temperature. Alkyl and aryl sulfides were oxidized to the corresponding sulfoxides or sulfones in excellent yields. Secondary alcohols were also converted to the corresponding esters/lactones and aldehydes to methyl esters in good yields. Moreover, aliphatic tertiary amines and substituted pyridines were oxidized to N-oxides.
- Shokrolahi, Arash,Zali, Abbas,Keshavarz, Mohammad Hossein
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experimental part
p. 1427 - 1432
(2012/04/18)
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- Synthesis and molecular docking studies of novel 2-chloro-pyridine derivatives containing flavone moieties as potential antitumor agents
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A series of novel 2-chloro-pyridine derivatives containing flavone, chrome or dihydropyrazole moieties as potential telomerase inhibitors were synthesized. The bioassay tests showed that compounds 6e and 6f exhibited some effect against gastric cancer cell SGC-7901 with IC50 values of 22.28 ± 6.26 and 18.45 ± 2.79 μg/mL, respectively. All title compounds were assayed for telomerase inhibition by a modified TRAP assay, the results showed that compound 6e can strongly inhibit telomerase with IC50 value of 0.8 ± 0.07 μM. Docking simulation was performed to position compound 6e into the active site of telomerase (3DU6) to determine the probable binding model.
- Liu, Xin-Hua,Liu, Hui-Feng,Shen, Xu,Song, Bao-An,Bhadury, Pinaki S.,Zhu, Hai-Liang,Liu, Jin-Xing,Qi, Xing-Bao
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scheme or table
p. 4163 - 4167
(2010/08/20)
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- Selective oxidation of pyridine to pyridine-N-oxide with hydrogen peroxide over Ti-MWW catalyst
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The oxidation of pyridine to pyridine-N-oxide (PNO) with hydrogen peroxide has been investigated on various titanosilicate catalysts. Superior to other titanosilicates like TS-1, Ti-Beta and Ti-MOR, Ti-MWW showed a higher catalytic activity and product se
- Xie, Wei,Zheng, Yuting,Zhao, Song,Yang, Junxia,Liu, Yueming,Wu, Peng
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experimental part
p. 114 - 118
(2011/01/04)
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- A safe, convenient and efficient method for the preparation of heterocyclic N-oxides using urea·hydrogen peroxide
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A novel, convenient, and high-yielding method has been developed for the preparation of heterocyclic N-oxides. The reaction uses the urea·hydrogen peroxide addition complex as a peroxide source for the in situ generation of trifluoroperacetic acid. The advantages of this method are easy handling of a stable, solid oxidant; high yields and simple removal of excess reagents and by-products.
- Rong, Dawen,Phillips, Victoria A.,Rubio, Ramón Sánchez,ángeles Castro, Ma,Wheelhouse, Richard T.
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scheme or table
p. 6933 - 6935
(2009/04/07)
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- Syntheses of sterically hindered zwitterionic pyridinium phenolates as model compounds in nonlinear optics
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Pyridinium phenolates possess a dissymmetric delocalised π-electron system providing a huge quadratic nonlinearity. They are a promising class of molecules for applications in photoelectronics and photonics. Semiempirical calculations indicate that the interplanar angle between the two aromatic rings leads to enhancement in the NLO properties of these compounds. The confirmation of this feature may be provided by the study of a new series of sterically hindered pyridinium phenolates 2a-e bearing two tert-butyl substituents at the ortho position(s) of the phenolate functionality. Such bulky groups would enhance the solubility of zwitterions in organic solvents and would limit the formation of aggregates. Their efficient preparations by using Suzuki cross-coupling reactions involving 3,5-dialkylated 4-bromopyridine N-oxides are described herein. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Diemer, Vincent,Chaumeil, Helene,Defoin, Albert,Fort, Alain,Boeglin, Alex,Carre, Christiane
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experimental part
p. 1767 - 1776
(2009/04/11)
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- Equilibrium of acyl transfer between pyridine N-oxides and their acylonium salts
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Transfer of acyl groups from N-acyloxypyridinium salts to pyridine N-oxides in acetonitrile was studied. The equilibrium constants of acyl exchange were determined. These quantities vary in the range covering eight orders of magnitude, depending on the st
- Rubachenko,Schroeder,Chotii,Kovalenko,Red'ko,Lenska
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p. 1241 - 1246
(2008/12/22)
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- Facile, one-step production of niacin (vitamin B3) and other nitrogen-containing pharmaceutical chemicals with a single-site heterogeneous catalyst
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Niacin (3-picolinic acid), which is extensively used as vitamin B 3 in foodstuffs and as a cholesterol-lowering agent, along with other oxygenated products of the picolines, 4-methylquinoline, and a variety of pyrimidines and pyridazines, may be produced in a single-step, environmentally benign fashion by combining single-site, open-structure, heterogeneous catalysts witha solid source of active oxygen, namely acetyl peroxyborate (APB), in the absence of an organic solvent. The high activities, selectivities, and the relatively mild conditions employed with this single-site heterogeneous catalyst, coupled with ease of transport, storage, and stability of the solid oxidant, augurs well for the future use of APB in conjunction with other open-structure, single-site catalysts for fine-chemical, pharmaceutical, and agrochemical applications.
- Raja, Robert,Thomas, John Meurig,Greenhill-Hooper, Michael,Ley, Steven V.,Almeida Paz, Filipe A.
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experimental part
p. 2340 - 2348
(2009/04/11)
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- Rhenium-catalyzed highly efficient oxidations of tertiary nitrogen compounds to N-oxides using sodium percarbonate as oxygen source
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Sodium percarbonate was found to be an ideal and efficient oxygen source for the oxidation of tertiary nitrogen compounds to N-oxides in excellent yields in presence of various rhenium-based catalysts under mild reaction conditions. Georg Thieme Verlag Stuttgart.
- Jain, Suman L.,Joseph, Jomy K.,Sain, Bir
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p. 2661 - 2663
(2008/09/16)
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- Preparation, characterization, and aquation kinetics of pyridine N-oxide complexes of chromium(III)
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A series of (H2O)5Cr(X-pyO)3+ ions (pyO = pyridine N-oxide, X = H, 3-CH3, 4-CH3, 4-OCH3, 4-NO2) were prepared by the reduction of the corresponding pyridine N-oxide adducts of diperoxochromium(VI) species with acidic ferrous perchlorate. The (H2O)5Cr(X-pyO)3+ complexes undergo aquation to yield Cr(H2O)63+ and X-pyO according to the rate law kobs = ko + k -1[H+]-1. The values of the rate constants extrapolated to 298 K at 1.0 M ionic strength are: k0 = 2.80 × 10-6 s-1, k-1 = 1.86 × 10-8 M s-1 (X = 4-NO2); 7.80 × 10-8, 6.27 × 10-10 (H); 4.80 × 10-8, 3.20 × 10 -10 (3-CH3); 3.05 × 10-8, 1.60 × 10-10 (4-CH3); and 2.37 × 10-9, 4.76 × 10-11 (4-OCH3). The reaction of the 4-OCH 3 complex exhibits two additional terms in the rate law, k 1[H+] + k-2[H+]-2. The binding of 4-OCH3-pyO to chromium is suggested to take place through the methoxy group. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Kotowski, Mirjana,Marcec, Radovan,Butkovic, Vjera,Bakac, Andreja,Orhanovic, Matko
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p. 2894 - 2899
(2007/10/03)
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- A Simple and Efficient Method for the Preparation of Heterocyclic N-Oxide
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Pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2,4-dimethylpyridine, 2,6-dimethylpyridine, quinoline, isoquinoline and 2-chloropyridine are readily oxidized to their N-oxides with a solution of trichloroisocyanuric acid, acetic acid, sodium acetate and water in acetonitrile and methylene dichloride in 78%-90% yields.
- Zhong, Ping,Guo, Sheng-Rong,Song, Cai-Sheng
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p. 247 - 253
(2007/10/03)
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- Bromamine-T/RuCl3 as an efficient system for the oxidation of tertiary amines to N-oxides
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A variety of tertiary amines were efficiently and selectively oxidized to the corresponding N-oxides by bromamine-T using ruthenium trichloride as catalyst in alkaline (pH8.4) acetonitrile/water (1:1) at 80°C.
- Sharma, Vishal B.,Jain, Suman L.,Sain, Bir
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p. 4281 - 4283
(2007/10/03)
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- An unconventional cobalt-catalyzed aerobic oxidation of tertiary nitrogen compounds to N-oxides
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A simple system, simple workup, and excellent yields make the new method for the oxidation of tertiary nitrogen compounds described in Equation (1) an attractive, environmentally acceptable synthetic tool. Molecular oxygen serves as the oxygen source and no sacrificial agents are required.
- Jain, Suman L.,Sain, Bir
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p. 1265 - 1267
(2007/10/03)
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- Rate and Equilibrium Constants of Dimethylcarbamoyl Transfer between Pyridine N-Oxides
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Dimethylcarbamoyl transfer from N-acyloxypyridinium salts to pyridine N-oxides in acetonitrile occurs in one stage by the forced concerted SN2 mechanism. The rate and equilibrium of the reaction are fairly described by the Bronsted equation. The Marcus equation provides a much higher quality of reactivity predictions.
- Schroeder,Rybachenko,Chotii,Kovalenko,Grebenyuk,Lenska,Eitner
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p. 455 - 462
(2007/10/03)
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- The Rate and Equilibrium Constants for N-, O-Acyl Transfer
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Reactions with dimethylcarbamoyl group transfer from N-acylpyridinium salts to pyridine N-oxides and from N-acyloxypyridinium salts to pyridines in acetonirile solutions were studied. Their rate and equilibrium constants and activation parameters were determined. The reactions were shown to be one-step and to follow the SN2 mechanism. Equations relating the rate and equilibrium parameters of the N-O and O-N acyl transfer reactions to the basicity of the nucleophile and outgoing group were obtained.
- Rybachenko,Chotii,Kovalenko,Shreder
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p. 1695 - 1698
(2007/10/03)
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- Ruthenium catalyzed oxidation of tertiary nitrogen compounds with molecular oxygen: An easy access to N-oxides under mild conditions
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A variety of tertiary nitrogen compounds have been efficiently oxidized to their corresponding N-oxides in excellent yields with molecular oxygen as a sole oxidant and ruthenium trichloride as catalyst.
- Jain, Suman L.,Sain, Bir
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p. 1040 - 1041
(2007/10/03)
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- An efficient synthesis of heterocyclic N-oxides over molecular sieve catalyst
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Heterocyclic N-oxides have been synthesized in very high yields over redox molecular sieve catalysts in the presence of H2O2.
- Prasad, M. Ramakrishna,Kamalakar, G.,Madhavi, G.,Kulkarni, S. J.,Raghavan, K. V.
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p. 1577 - 1578
(2007/10/03)
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