- NaI/PPh3-Mediated Photochemical Reduction and Amination of Nitroarenes
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A mild transition-metal- and photosensitizer-free photoredox system based on the combination of NaI and PPh3 was found to enable highly selective reduction of nitroarenes. This protocol tolerates a broad range of reducible functional groups such as halogen (Cl, Br, and even I), aldehyde, ketone, carboxyl, and cyano. Moreover, the photoredox catalysis with NaI and stoichiometric PPh3 provides also an alternative entry to Cadogan-type reductive amination when o-nitrobiarenes were used.
- Qu, Zhonghua,Chen, Xing,Zhong, Shuai,Deng, Guo-Jun,Huang, Huawen
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supporting information
p. 5349 - 5353
(2021/07/21)
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- Highly Efficient and Chemoselective Hydrogenation of Nitro Compounds into Amines by Nitrogen-Doped Porous Carbon-Supported Co/Ni Bimetallic Nanoparticles
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A novel Co/Ni bimetallic nanoparticle supported by nitrogen-doped porous carbon (NPC), Co5/Ni@NPC-700, exhibits high conversion, chemoselectivity, and recyclability in the hydrogenation of 16 different nitro compounds into desired amines with hydrazine hydrate under mild conditions. The synergistic effects of Co/Ni bimetal nanoparticles and the NPC-supported porous honeycomb structure with more accessible active sites may be responsible for the high catalytic hydrogenation performance.
- Shen, Zeyu,Hong, Lirui,Zheng, Baishu,Wang, Guanyu,Zhang, Beibei,Wang, Zhaoxu,Zhan, Feiyang,Shen, Shaohua,Yun, Ruirui
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supporting information
p. 16834 - 16839
(2021/11/17)
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- A Pod-like Core-Shell Catalyst with High Reduction Performance Under Mild Conditions
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Recent years, tubular structure as the carrier loading nanoparticles has been reported more and more frequently which is synthesized by pyrolysis polyhedral MOFs. However, the construct mechanism has not been referred. Herein, a tubular structure has been designed by calcining modified ZIF-8 under different temperature to reveal the formation process of tubular carbon from the polyhedron. As a result, a pod-like core-shell catalyst of Fe/Fe3C-900 has been obtained and exhibits a high activity and excellent substituent tolerance for the reduction of nitro groups under mild conditions.
- Du, Liting,He, Lei,Li, Tuanhui,Luo, Shizhou,Xu, Fagong,Yun, Ruirui,Zhan, Feiyang,Zhang, Beibei,Zheng, Baishu
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- Copper(II) complex with oxazoline ligand: Synthesis, structures and catalytic activity for nitro compounds reduction
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The Cu(II) complexes bearing bisoxazolines, tridentate pincer pybox and terpyridine ligands have been synthesized and fully characterized. The molecular structures of copper complexes 1a and 1c were confirmed by single-crystal X-ray diffraction methods. These copper complexes highly catalyzed nitro compounds reduction to aniline and its derivatives in the presence of NaBH4 reducing agent in water solvent. The complex 1e was an efficient catalyst toward nitro compounds reduction with wide functional group substrate scope and aliphatic nitro compounds.
- Du, Jun,Gao, Li-Li,Jia, Wei-Guo,Li, Mei,Zhi, Xue-Ting
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- Synthesis, characterization, and catalytic activity of half-sandwich ruthenium complexes with pyridine/phenylene bridged NHC = E (NHC = N-heterocyclic carbene, E = S, Se) ligands
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Three half-sandwichruthenium(II) complexes with pyridine/phenylene bridged NHC = E (NHC = N-heterocyclic carbene, E = S, Se) ligands [Ru(p-cymene)L](PF6)1–2 (1a–1c, L = ligand) were synthesized and characterized. All ruthenium complexes were fully characterized by 1H and 13C NMR spectra, mass spectrometry, and single-crystalX-ray diffraction methods. Moreover, the half-sandwich ruthenium complexes with NHC = E ligands showed highly catalytic activities towards to the tandem dehydrogenation of ammonia borane (AB) and hydrogenation of R–NO2 to R–NH2 at 353 K in water.
- Jia, Wei-Guo,Du, Teng-Teng,Gao, Li-Li,Du, Jun
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- Fe/Fe2O3@N-dopped Porous Carbon: A High-Performance Catalyst for Selective Hydrogenation of Nitro Compounds
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Herein, we designed and prepared a novel Fe/Fe2O3-based catalyst, in which a remarkable synergistic effect has been revealed between Fe and Fe2O3 encapsulated in N-doping porous carbon. The Fe-based catalysts were fabricated via pyrolysis a mixture of MIL-101(Fe) and melamine. The catalyst exhibits exceptionally high catalytic activity (TOFs up to 8898 h?1 which is about 100 times higher than the similar kinds of catalysts) and chemoselectivity for nitroarene reduction under mild conditions.
- Yun, Ruirui,Hong, Lirui,Ma, Wanjiao,Jia, Weiguo,Liu, Shoujie,Zheng, Baishu
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p. 724 - 728
(2019/01/04)
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- High Selectivity of Hydrogenation Reaction over Co0.15@C/PC Catalyst at Room Temperature
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In the field of catalysis, material scientists pay much attention to tuning the activity and chemoselectivity of metal nanoparticles. Herein, we design and successfully synthesize a series of Co NPs which show high performance on hydrogenation of nitroarenes with both activity and chemoselectivity. Co0.15@C/PC preferentially activates the -C=O bond over -NO2 in water with ammonia borane (AB); however, when the hydrogen source is changes to hydrazine hydrate (HH), the results are the opposite. The Co-based catalyst exhibits exceptionally high catalytic activity (with a TOF value of 10512 h-1, which is approximately 100 times than the akin catalysts) and chemo-selectivity for the hydrogenation of nitro compounds under mild conditions. Additionally, the catalyst can be separated easily by a magnet and shows prominent stabilit, which means that it can be reused for at least 10 cycles.
- Yun, Ruirui,Ma, Wanjiao,Wang, Suna,Jia, Weiguo,Zheng, Baishu
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- Development and Scale-up of Continuous Electrocatalytic Hydrogenation of Functionalized Nitro Arenes, Nitriles, and Unsaturated Aldehydes
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Electrolysis flow reactors based on the filter-press architecture of redox flow batteries have proven to be effective and scalable toward the production of commercially relevant, pharmaceutical quantities of anilines (>500 kg/year) from halogen-, hydroxyl-, and carbonyl-substituted nitroarenes. Turbulent flow through the carbon felts on which the catalysts were supported facilitated scaling toward production levels because it conferred on the reactors scale-independent, plug flow-like residence time distributions and high mass transfer coefficients. Equipping the cells with microreference electrodes made it possible to transfer reaction conditions first developed in batch systems to the continuous flow reactors. The catalysts prepared by incipient wetness impregnation of metal salts into lightly oxidized carbon felt supports were readily generalizable.
- Egbert, Jonathan D.,Thomsen, Edwin C.,O'Neill-Slawecki, Stacy A.,Mans, Douglas M.,Leitch, David C.,Edwards, Lee J.,Wade, Charles E.,Weber, Robert S.
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p. 1803 - 1812
(2019/08/15)
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- Fe/Fe3C Encapsulated in N-Doped Carbon Tubes: A Recyclable Catalyst for Hydrogenation with High Selectivity
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Herein, a series of Fe-based catalysts have been designed and prepared by grinding a mixture of MIL-88d and melamine, and then the mixture was followed by pyrolysis. An unusual Fe/Fe3C-activated site is uniformly encapsulated in the N-doped carbon tubes obtained by pyrolysis of the film-like nanocrystals of MIL-88d. Experimental characterizations and theoretical calculations demonstrate that the surface N sites can effectively trap the nitrobenzene and aniline by their phenyl groups with the formation of three C-N bonds that made the catalyst exhibit excellent catalytic activity (turnover frequencies of ≤11268 h-1 calculated on the basis of nitrobenzene) and chemoselectivity for the reduction of nitro derivatives under facile conditions.
- Yun, Ruirui,Zhang, Shi,Ma, Wanjiao,Lv, Xiao,Liu, Shoujie,Sheng, Tian,Wang, Suna
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supporting information
p. 9469 - 9475
(2019/08/20)
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- N-doped graphitic carbon-improved Co-MoO3 catalysts on ordered mesoporous SBA-15 for chemoselective reduction of nitroarenes
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Metallic Co-MoO3 catalysts supported on ordered mesoporous SBA-15 were first prepared through in situ reaction of SBA-15-supported Co-Mo oxides with 1,10-phenanthroline. The resulting Co-MoO3/NC@SBA-15 catalysts with N-doped carbon (NC) exhibited high catalytic activity and chemoselectivity for selective reduction of various functionalized nitroarenes to the corresponding arylamines in ethanol with hydrazine hydrate at near room temperature (30 °C). For reduction of all tested substrates (28 examples), the catalyst could afford a conversion of >99% and arylamine selectivity of >99%. The excellent catalytic performance of the Co-MoO3/NC@SBA-15 was attributed to the Co-Nχ(C)-Mo active sites generated through the interaction between the surface Co-Nχ(C) and MoO3 species, promoting the dissociation of hydrazine molecule into the active H* species for the reduction of nitro groups. After the seventh cycle for reduction of 4-methoxylnitrobenzene, the 2%Co-MoO3/NC@SBA-15 showed little change in catalytic performance, textural properties, size and dispersion of metal species and valence states of elements, indicating high stability and recyclability.
- Huang, Haigen,Liang, Xiangcheng,Wang, Xueguang,Sheng, Yao,Chen, Chenju,Zou, Xiujing,Lu, Xionggang
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p. 127 - 137
(2018/05/04)
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- Synthesis of 2, 6 - diamino-toluene
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The invention relates to a method for synthesizing 2, 6-diaminotoluene. The method comprises the following step: by using 2-chlorine-6-nitrotoluene as a raw material, carrying out reduction reaction and ammonolysis reaction to obtain 2, 6-diaminotoluene. The process is simple in synthesis route, easy to control the reaction and few in three wastes generated at the working segments, thereby meeting the green and environmental friendly requirements; and moreover, produced 2, 6-diaminotoluene is high in purity and excellent in quality, so that the method is an excellent industrial route.
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Paragraph 0026-0027
(2017/01/31)
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- Highly chemoselective reduction of nitroarenes over non-noble metal nickel-molybdenum oxide catalysts
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The chemoselective reduction of nitroarenes is an important transformation for the production of arylamines, which are the primary intermediates in the synthesis of pharmaceuticals, agrochemicals and dyes. Heterogeneous non-noble metal nickel-molybdenum oxide catalysts supported on ordered mesoporous silica SBA-15 (Ni-MoO3/CN@SBA-15) were prepared for the first time by treating SBA-15-supported nickel-molybdenum oxide materials with 1,10-phenanthroline, and exhibited unprecedented catalytic activity and chemoselectivity for the reduction of various substituted nitroarenes to the corresponding aromatic amines in ethanol with hydrazine hydrate as a hydrogen donor under mild conditions owing to the synergistic effect of metal Ni and MoO3 species, affording excellent yields of >99% within very short reaction periods (≤60 min). The Ni-MoO3/CN@SBA-15 catalysts were highly stable and could easily be recovered by simple filtration or by an external magnetic field for at least ten recycling reactions without any observable loss of catalytic performance or leaching of metal components.
- Huang, Haigen,Wang, Xueguang,Li, Xu,Chen, Chenju,Zou, Xiujing,Ding, Weizhong,Lu, Xionggang
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p. 809 - 815
(2017/08/15)
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- Solvent-Free Selective Hydrogenation of Nitroarenes Using Nanoclusters of Palladium Supported on Nitrogen-Doped Ordered Mesoporous Carbon
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The selective hydrogenation of nitroarenes is a key transformation for the production of aromatic amines, which are primary intermediates in the synthesis of pharmaceuticals, agrochemicals, and dyes. However, most reaction processes require toxic organic solvents and suffer from poor selectivity in the presence of other reducible groups. Herein, we report a successful example of nanoclusters of ultrafine Pd supported on N-modified ordered mesoporous CMK-3 carbon (Pd/N-CMK-3) prepared by a facile two-step impregnation route with aqueous solutions of 1,10-phenanthroline and H2PdCl4 that hydrogenated various nitroarenes highly efficiently and selectively to the corresponding aromatic amines with hydrogen in the absence of solvent. The Pd/N-CMK-3 catalyst could be recovered easily for multiple recycling reactions without a loss of catalytic performance.
- Huang, Haigen,Wang, Xueguang,Tan, Mingwu,Chen, Chenju,Zou, Xiujing,Ding, Weizhong,Lu, Xionggang
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p. 1485 - 1489
(2016/05/02)
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- Fe3O4@graphene oxide composite: A magnetically separable and efficient catalyst for the reduction of nitroarenes
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We reported a facile co-precipitation method to prepare a highly active Fe3O4@graphene oxide (Fe3O4@GO) composite catalyst, which was fully characterized by means of X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and N2 adsorption-desorption measurements. The results demonstrated that the Fe3O4 nanoparticles (Fe 3O4 NPs) with a small diameter of around 12 nm were densely and evenly deposited on the graphene oxide (GO) sheets. The as-prepared Fe3O4@GO composite was explored as a catalyst to reduce a series of nitroarenes for the first time, which exhibited a great activity with a turnover frequency (TOF) of 3.63 min-1, forty five times that of the commercial Fe3O4 NPs. The dosages of catalyst and hydrazine hydrate are both less than those reported. Furthermore, the composite catalyst can be easily recovered due to its magnetic separability and high stability.
- He, Guangyu,Liu, Weifeng,Sun, Xiaoqiang,Chen, Qun,Wang, Xin,Chen, Haiqun
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p. 1885 - 1890
(2013/04/24)
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- Highly selective hydrogenation of halonitroaromatics to aromatic haloamines by ligand modified Ni-based catalysts
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Ligand modification of Ni-based catalysts by coordination of dicyandiamide to Ni metal leads to enhanced selectivity for the selective hydrogenation of halonitroaromatics. The selectivity of above 99.9% to aromatic haloamines can be achieved at the conversion of 100%. The results of H2-TPD and FT-IR experiments show that Ni-H+ species possessing the properties of Lewis acid site on the surface of Raney Ni could be responsible for the hydrodehalogenation. When Raney Ni was treated by dicyandiamide, Ni -H+ species interacted with N atom from the dicyandiamide. This interaction was stable even at reaction temperature, which reduced the possibility to form the intermediate state of ArCl?H+Ni -. And then CCl bond could not be polarized and activated. The hydrodechlorination process was suppressed effectively.
- Lu, Chun Shan,Lv, Jing Hui,Ma, Lei,Zhang, Qun Feng,Feng, Feng,Li, Xiao Nian
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experimental part
p. 545 - 548
(2012/06/16)
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- Substituted indoles as alpha-1 agonists
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This invention relates to compounds which are alpha-1 receptor agonists, preferably alpha-1A/L receptor agonists, and which are represented by Formula I: wherein m, A, X, Y, R1, R2, R3, R4 and R5 are as defined in the specification; or individual isomers, racemic or non-racemic mixtures of isomers, or pharmaceutically acceptable salts or solvates thereof. The invention further relates to pharmaceutical compositions containing such compounds, methods for their use as therapeutic agents, and methods of preparation thereof.
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- PROCESS FOR THE PREPARATION OF SUBSTITUTED HALOGENATED ANILINE
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A process for the preparation of substituted halogenated anilines from substituted halogenated 1-chlorobenzenes which comprisesa) reacting a substituted halogenated 1-chlorobenzene selectively with an imine in the presence of a transition metal catalyst complex and a base to form an N-aryl imine; b) hydrolyzing the N-aryl imine; andc) isolating the substituted halogenated aniline.
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- Indium metal as a reducing agent in organic synthesis
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The low first ionisation potential (5.8 eV) of indium coupled with its stability towards air and water, suggest that this metallic element should be a useful reducing agent for organic substrates. The use of indium metal for the reduction of C=N bonds in imines, the heterocyclic ring in benzo-fused nitrogen heterocycles, of oximes, nitro compounds and conjugated alkenes and the removal of 4-nitrobenzyl protecting groups is described. Thus the heterocyclic ring in quinolines, isoquinolines and quinoxalines is selectively reduced using indium metal in aqueous ethanolic ammonium chloride. Treatment of a range of aromatic nitro compounds under similar conditions results in selective reduction of the nitro groups; ester, nitrile, amide and halide substituents are unaffected. Likewise indium in aqueous ethanolic ammonium chloride is an effective method for the deprotection of 4-nitrobenzyl ethers and esters. Indium is also an effective reducing agent under non-aqueous conditions and α-oximino carbonyl compounds can be selectively reduced to the corresponding N-protected amine with indium powder, acetic acid in THF in the presence of acetic anhydride or di-tert-butyl dicarbonate. Conjugated alkenes are also reduced by indium in THF-acetic acid.
- Pitts,Harrison,Moody
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p. 955 - 977
(2007/10/03)
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- Catalysts for alkoxylation reactions
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Catalysts producing a sharply peaked alkoxylation distribution during the alkoxylation of organic materials comprise mixtures of BF3 and metal alkyls or metal alkoxides, SiF4 and metal alkyls or metal alkoxides, or mixtures of these catalysts.
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- Methods of alkoxylation
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Catalysts comprising mixtures of HF and metal alkoxides and mixed metal alkoxides produce a sharply peaked alkoxylation distribution during the alkoxylation of organic materials.
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- Quinoline carboxylic acid derivatives
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A quinoline carboxylic acid derivative of the general formula STR1 [wherein R1 and R2 are a lower alkyl group, respectively, and R3 is a halogen atom or 1-piperazinyl group] and its salt are of value as an antimicrobial agent for medical treatment and agricultural and horticultural uses.
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- Catalysts for alkoxylation reactions
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Catalysts and a method of using said catalysts for the alkoxylation of a variety of materials is disclosed. Catalysts so described produce alkoxylates having a very sharp alkoxylate distribution. The catalysts are supported and unsupported dialkoxy and dialkyl metal fluorides and halides and alkyl metal difluorides and dihalides.
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- 4-Hydroxy-1,2-Benzisothiazol-3(2H)-one-1,1-dioxides and salts thereof
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Compounds of the formula STR1 wherein R1 is hydrogen or hydroxyl, and non-toxic, pharmacologically acceptable salts thereof formed with inorganic or organic bases. The compounds as well as their salts are useful as sweetening agents.
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