- Oxidative dehydrogenation of hydrazines and diarylamines using a polyoxomolybdate-based iron catalyst
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We report an efficient method for the oxidative dehydrogenation of hydrazines and diarylamines in aqueous ethanol using Anderson-type polyoxomolybdate-based iron(iii) as a catalyst and hydrogen peroxide as an oxidant. A series of azo compounds and tetraarylhydrazines were obtained in moderate to excellent yields. The reaction conditions and substrate scopes are complementary or superior to those of more established protocols. In addition, the catalyst shows good stability and reusability in water. The preliminary mechanistic studies suggest that a radical process is involved in the reaction.
- Huang, Lei,Qiu, Shiqin,Wei, Yongge,Xie, Jingyan,Yu, Han,Zeng, Xianghua,Zhao, Weizhe
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supporting information
p. 7677 - 7680
(2021/08/09)
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- Bismuth Amides Mediate Facile and Highly Selective Pn–Pn Radical-Coupling Reactions (Pn=N, P, As)
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The controlled release of well-defined radical species under mild conditions for subsequent use in selective reactions is an important and challenging task in synthetic chemistry. We show here that simple bismuth amide species [Bi(NAr2)3] readily release aminyl radicals [NAr2]. at ambient temperature in solution. These reactions yield the corresponding hydrazines, Ar2N?NAr2, as a result of highly selective N?N coupling. The exploitation of facile homolytic Bi?Pn bond cleavage for Pn?Pn bond formation was extended to higher homologues of the pnictogens (Pn=N–As): homoleptic bismuth amides mediate the highly selective dehydrocoupling of HPnR2 to give R2Pn?PnR2. Analyses by NMR and EPR spectroscopy, single-crystal X-ray diffraction, and DFT calculations reveal low Bi?N homolytic bond-dissociation energies, suggest radical coupling in the coordination sphere of bismuth, and reveal electronic and steric parameters as effective tools to control these reactions.
- Oberdorf, Kai,Hanft, Anna,Ramler, Jacqueline,Krummenacher, Ivo,Bickelhaupt, F. Matthias,Poater, Jordi,Lichtenberg, Crispin
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p. 6441 - 6445
(2021/02/01)
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- Method for realizing N-N coupling of secondary arylamine by utilizing electrochemical reaction
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The invention relates to the technical field of organic synthesis, and discloses a method for realizing the N-N coupling of secondary arylamine by utilizing electrochemical reaction, i.e., in a deviceprovided with an anode and a cathode, an Nmethylaniline
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Paragraph 0050-0052
(2021/04/14)
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- A Highly Active, Recyclable and Cost-Effective Magnetic Nanoparticles Supported Copper Catalyst for N-arylation Reaction
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Abstract: The immobilization of a copper complex by covalent anchoring of 2-hydroxybenzophenone on the surface of amine-functionalized magnetic nanoparticles was reported. The structure and morphology of the catalyst was characterized by different techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron micrograph (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), vibrating sample magnetometer (VSM) and inductively coupled plasma (ICP) spectroscopy. This efficient and cost effective catalyst was applied in the N-arylation reaction and the products were obtained in good to excellent yields in short reaction times. The cost-effective catalyst demonstrated high stability, which could be facilely separated from the reaction mixture by applying an external magnet and recycled at least four times with only a slight decrease in its activity. Graphic Abstract: [Figure not available: see fulltext.]
- Zahedi, Razieh,Asadi, Zahra,Firuzabadi, Fahimeh Dehghani
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- Iodine-mediated oxidative N-N coupling of secondary amines to hydrazines
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An I2-mediated N-N coupling reaction has been established for oxidative dimerization of N-aryl aminopyridines to a variety of novel hydrazine derivatives under mild conditions. This synthetic method does not require use of transition metals and
- Ren, Linning,Wang, Manman,Fang, Benyao,Yu, Wenquan,Chang, Junbiao
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p. 3446 - 3450
(2019/04/01)
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- Transition-Metal-Free Dehydrogenative N–N Coupling of Secondary Amines with KI/KIO4
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A transition-metal-free method for the dehydrogenative N–N coupling of secondary amines has been accomplished. This oxidative KI/KIO4 protocol is mild and operationally simple. A diverse range of diphenylamines, carbazoles, and N-alkylanilines readily undergo N–N homo-coupling effectively. Notably, the N–N cross-coupling of two different arylamines is also demonstrated, which provides a straightforward approach to the complex N–N structures.
- Yin, Dehang,Jin, Jian
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supporting information
p. 5646 - 5649
(2019/08/21)
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- Cu-Catalyzed Aerobic Oxidative N-N Coupling of Carbazoles and Diarylamines Including Selective Cross-Coupling
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A Cu-catalyzed method has been identified for aerobic oxidative dimerization of carbazoles and diarylamines to the corresponding N-N coupled bicarbazoles and tetraarylhydrazines. The reactions proceed under mild conditions (1 atm O2, 60-80 °C)
- Ryan, Michael C.,Martinelli, Joseph R.,Stahl, Shannon S.
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supporting information
p. 9074 - 9077
(2018/07/21)
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- Reduction of nitroarenes, azoarenes and hydrazine derivatives by an organic super electron donor
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Reduction of nitrobenzene by excess organic electron donor, 12, affords diphenylhydrazine in a reaction where azobenzene oxide and azobenzene are likely intermediates. No cleavage of the N-N σ-bond is seen under photoactivation conditions, whereas traces are seen under thermal activation. Hydrazone derivatives were prepared to explore the cleavage of N-N σ-bonds; the results show that a low-lying LUMO assists the transition state for accepting an electron, and the stabilisation that the potential fragments from N-N bond cleavage afford to the fragments is important in determining whether cleavage is observed.
- Cumine, Florimond,Palumbo, Fabrizio,Murphy, John A.
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p. 5539 - 5545
(2018/05/07)
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- Cu(I) catalyzed dehydrogenative homo coupling of aromatic amines under simple and mild reaction conditions
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An efficient protocol for the synthesis of a variety of azobenzenes and hydrazines from aromatic amines under mild reaction conditions is developed using Cu(I) catalyst. The copper cataylst used in this study comprises of CuBr, DMAP and AIBN. The plausible proposed mechanism for this dehydrogenative homo coupling of aromatic amines is depicted.
- Reddy, C.B. Rajashekhar,Reddy, Sabbasani Rajasekhara,Naidu, Shivaji
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- Facile Cu(I)-catalyzed oxidative coupling of anilines to azo compounds and hydrazines with diaziridinone under mild conditions
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A mild and highly efficient Cu(I)-catalyzed oxidative coupling of anilines is described. Various primary and secondary anilines can be efficiently coupled under mild conditions to the corresponding azo compounds and hydrazines in high yields. This method provides a direct and practical access to these compounds and is also amenable to gram scale with no special precautions to exclude air or moisture.
- Zhu, Yingguang,Shi, Yian
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supporting information
p. 1942 - 1945
(2013/06/04)
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- Reduction of hydrazines to amines with aqueous solution of titanium(iii) trichloride
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N-N bond cleavage in hydrazines is widely used in the preparation of amines and thus occupies a significant place in organic synthesis. In this paper, we report a new method for the reductive cleavage of N-N bonds in hydrazines by commercially available and cheap aqueous titanium(iii) trichloride. The reaction proceeds smoothly under a broad pH range from acidic to neutral and basic conditions to afford amines in good yields. This method is compatible with substrates containing functionalities such as C-C double bonds, benzyl-nitrogen bonds, benzyloxy and acyl groups. The Royal Society of Chemistry 2011.
- Zhang, Yan,Tang, Qiang,Luo, Meiming
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supporting information; experimental part
p. 4977 - 4982
(2011/08/05)
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- Fast synthesis of hydrazine and Azo derivatives by oxidation of rare-earth-metal-nitrogen bonds
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A novel N-N coupling reaction was developed through the oxidation of rare-earth-metal-nitrogen bonds produced by treatment of the easily available rare-earth-metal amides [(Me3Si)2N]3RE(μ-Cl) Li(THF)3 with aromatic primary or secondary amines. The reaction provides the symmetrical or unsymmetrical azo compounds and hydrazine derivatives in good to high yields within a very short time under mild conditions.
- Zhang, Lijun,Xia, Jing,Li, Qinghai,Li, Xihong,Wang, Shaowu
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scheme or table
p. 375 - 378
(2011/03/21)
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- Electrochemical oxidation of o-anisidine, p-anisidine, diphenylamine and o-toluidine at platinum electrode
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The oxidation of o-anisidine, p-anisidine, diphenylamine and o-toluidine was carried out at constant potential in non-aqueous system at platinum electrode. The electrolysis was carried out at controlled anodic potential in an electrochemical cell assembly containing reaction mixture, working as well as counter electrode and reference electrode. The oxidative products formed during the electrolysis of aromatic amines at platinum anode are discussed and reported here.
- Sharma, Laxmi Kant,Kumar, Sanjeev,Singh,Siddiqui
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experimental part
p. 1117 - 1123
(2011/05/05)
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- Adsorption and room temperature degradation of N-nitrosodiphenylamine on zeolites
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N-Nitrosodiphenylamine (NDPA) is selected as a model compound to reveal the specific adsorption and catalytic function of zeolites in the removal of carcinogenic nitrosamines from the environment. The bulky NDPA molecule is indeed adsorbed in the zeolite KA having a small aperture, by insertion of the -N-N=O group into the channel and involving a specific interaction between the nitrosamine and the zeolite. Degradation of NDPA at room temperature on zeolite is reported for the first time, revealing the potential applicability of zeolites to eliminate nitrosamines under mild conditions. The acidity of zeolite is the key factor determining its ability to degrade NDPA and, among the zeolites evaluated, Hβ is the most effective catalyst with an activity much higher than that of other zeolites at ambient temperature.
- Zhou, Chun Fang,Yun, Zhi Yu,Xu, Yang,Wang, Yi Meng,Chen, Jia,Zhu, Jian Hua
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p. 807 - 814
(2007/10/03)
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- LDA-promoted decomposition of benzenesulfenamides. A route to aminyl radicals by dioxygen oxidation of lithium amides
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The LDA-promoted decomposition of N-monosubstituted sulfenamides 1a-d occurs through the formation of thioaminyl anions, which undergo oxidation either at sulfur, with formation of sulfonamides, or at nitrogen, with formation of thioaminyl radicals, depending on the nature of the 4'-substituent. The reaction of N,N-disubstituted sulfenamides 1e-h proceeds through the intermediacy of a lithium complex capable of generating aminyl radicals via sulfenyl group transfer to the di-iso-propylamido anion and subsequent aerial oxidation of the resulting lithium amides 3e-h.
- Barbieri, Anna,Montevecchi, Pier Carlo,Nanni, Daniele,Navacchia, Maria Luisa
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p. 13255 - 13264
(2007/10/03)
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- Mechanism and Models for Copper Mediated Nucleophilic Aromatic Substitution. 2. A Single Catalytic Species from Three Different Oxidation States of Copper in an Ullmann Synthesis of Triarylamines
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Ullmann condensations of diarylamines with iodobenzenes has been investigated under homogeneous and a heterogeneous catalytic conditions with cupruos and cupric salts, as well as powered copper metal.Copper catalyzed condensation of diarylamines with iodoaromatics is relatively insensitive to substituent (for substituted iodobenzenes p=-0.25; for substituted diphenylamines p=1.09) but quite sensitive to halogen (k1/kBr.200).The first direct evidence for solution catalysis after filtration of a metal catalyzed reactions was obtained.Quantitative analysis of reaction rates, product yields, and catalyst characteristics leads to a comprehensive picture of the formation of soluble cuprous ions as the single active catalytic species under all conditions investigated.This hypothesis rationalizes many of the perplexing results which typify the literature associated with copper catalyzed nucleophilic aromatic substitution.
- Paine, Anthony James
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p. 1496 - 1502
(2007/10/02)
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- Kinetics of Oxidation of Unsubstituted and Substituted Diphenylamines by Alkaline Hexacyanoferrate(III)
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Oxidation of unsubstituted and substituted diphenylamines by alkaline hexacyanoferrate(III) at constant ionic strength in aqueous methanol is first order each in and , and independent of in the range studied.The Hammet plot y
- Dasgupta, Gopa,Mahanti, Mahendra K.
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p. 958 - 959
(2007/10/02)
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- Solid Phase Photoaddition of Benzophenone to Diphenylamine
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Solid phase photolysis at 366 nm of a mixture of benzophenone and diphenylamine as such and in pellets of KBr, KCl and NaCl gives 4-anilinophenyldiphenylmethanol (carbinol) and tetraphenylhydrazine (TPH) whereas excitation in the charge transfer band of the reactants leads to deactivation only.The reaction extent per unit time increases in the presence of oxalic acid with a concomitant decrease in THP yield.The reactions in the presence and absence of the acid follow different paths.The temperature effect is non-Arrhenius.It has been shown that the products are formed through a surface reaction where the ionic lattice of the solids helps the transport of the charged ions and prevents the back recombination of the geminate pairs which readily occurs in the aqueous phase.A mechanism consistent with the various observed features of the system has been given and it has been shown that TPH does not arise from triplet diphenylamine and is indeed a result of the unique configuration of molecules in the solid surface.
- Sidhu, K. S.,Bansal, W. R.,Jaswal, S. K.
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p. 910 - 914
(2007/10/02)
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- ESR Studies of Photochemical Reactions of Diphenylamines, Phenothiazines, and Phenoxazines
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Detailed photochemical reactions of diphenylamines, phenothiazines, and phenoxazines have been studied by the ESR technique.Our results show nitroxide radicals are the stable products of the photooxidation of both diphenylamines and phenothiazines, while cation radicals are the stable product of the photolyzed phenoxazines in the presence of air.
- Lin, Tien-Sung,Retsky, Joel
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p. 2687 - 2689
(2007/10/02)
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- CuCl-catalyzed Oxidative Coupling Reaction of Secondary Amines with Molecular Oxygen in Pyridine
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Oxidation of diphenylamine with molecular oxygen in the presence of CuCl in pyridine at room temperature to give tetraphenylhydrazine in a high yield was achieved by selecting suitable reaction conditions.N-methylaniline was also oxidized to give N,N'-dim
- Kajimoto, Tsunesuke,Takahashi, Hidetaka,Tsuji, Jiro
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p. 3673 - 3674
(2007/10/02)
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- Photocleavage of Diarylnitrosamines in Neutral Media
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N-Nitrosodiphenylamine, N-nitroso(2-nitrophenyl)phenylamine, N-nitroso(3-methylphenyl)phenylamine, and N-nitrosocarbazole were irradiated in degassed neutral solution to give the corresponding diarylamine as the initial photoproduct.The effects of changing solvents, concentrations, and substituents and of adding catalysts were examined.Quantum yield studies, sensitization work, and ESR studies were used to study the mechanism of this photolysis.
- Crumrine, David S.,Brodbeck, Charles M.,Dombrowski, Paul H.,Haberkamp, Thomas J.,Kekstas, Rita J.,et al.
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p. 4246 - 4249
(2007/10/02)
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- Reaction Pathways for Arylcarbamoyl Radicals and the Cyclization of o-Substituted Phenylcarbamoyl Radicals
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N-Arylcarbamoyl radicals generated from N-arylformamides with di-t-butyl peroxide (ButOOBut) in chlorobenzene at 110 deg C give rise to a series of reactions depending on the nature and the position of the substituent in the aromatic ring.When the aryl group is phenyl or p-chlorophenyl the following reactions on carbamoyl radicals occur: (i) loss of hydrogen with formation of aryl isocyanates, whereas the loss of carbon monoxide leads to arylamines via arylaminyl radicals; (ii) dimerization to NN'-diaryloxamides; (iii) aromatic substitution on chlorobenzene leading to N-arylbenzamides (ipso-substitution) and N-arylchlorobenzamides.The isocyanates trapped by t-butyl alcohol and arylamines give t-butyl N-arylcarbamates and NN'-diarylureas.With o-substituted N-phenylformamides intramolecular cyclization is observed as well; in fact, the N-(o-cyanophenyl)formamide affords isatin via addition of the carbamoyl radical to the cyano-group while the N-formamide gives 2-benzothiazolone and phenyl radicals through an SHi reaction on the sulphur atom; finally 2-formamidobiphenyls furnish phenanthridones in very high yields.
- Leardini, Rino,Tundo, Antonio,Zanardi, Giuseppe
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p. 3164 - 3167
(2007/10/02)
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- Cation Radical Intermediate in Benzidine Rearrangement of Pichydrazyl Radical
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The kinetics of benzidine rearrangement of pichydrazyl cation radical (I) has been studied and the rate of the reaction determined.The product analysis reveals that the reaction follows a non-concerted mechanism.
- Abdallah, A. Abdallah
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p. 994 - 995
(2007/10/02)
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