- Silver nanoparticles supported on P, Se-codoped g-C3N4 nanosheet as a novel heterogeneous catalyst for reduction of nitroaromatics to their corresponding amines
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P, Se-codoped g-C3N4 (PSeCN) nanosheet was in situ prepared by facile thermal polymerization of melamine, phosphonitrilic chloride trimer, and selenium black powder as the precursors. It was found as a suitable support for the immobilization of silver nanoparticles (Ag NPs). The prepared nanocatalyst was fully characterized via standard analysis methods including EDX, ICP-OES, XRD, FT-IR, SEM, TEM, and BET. This PSeCN/Ag nanocatalyst with a higher specific surface area compared with CN, showed excellent catalytic activity towards the reduction of several nitroaromatic compounds using sodium borohydride (NaBH4) in short reaction times with high efficiency and good selectivity in water as a green solvent. Significantly, the above-mentioned nanocomposite could be reused six times without appreciable loss of its catalytic activity.
- Elhampour, Ali,Heravi, Majid M.,Nemati, Firouzeh,Piri, Mohadese
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- Bakers' yeast-catalyzed ring opening of benzofuroxans: An efficient green synthesis of aryl-1,2-diamines
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A simple and inexpensive method for the reductive cleavage of N-O bond of benzofuroxans with bakers' yeast under nonfermenting condition in aqueous media was achieved. The procedure gives excellent yields of aryl-1,2-diamines. Copyright Taylor & Francis Group, LLC.
- Borah, Harsha N.,Prajapati, Dipak,Boruah, Romesh C.
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- Radical reactions in aqueous medium using (Me3Si)3SiH
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(Chemical Equation Presented) (Me3Si)3SiH was used as a successful reagent in a variety of radical-based transformations in water. The system comprising substrate, silane, and initiator (ACCN) mixed in aqueous medium at 100°C worked well for both hydrophilic and hydrophobic substrates, with the only variation that an amphiphilic thiol was also needed in case of the water-soluble compounds.
- Postigo, Al,Kopsov, Sergey,Ferreri, Carla,Chatgilialoglu, Chryssostomos
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- Efficient hydrogenation catalyst designing via preferential adsorption sites construction towards active copper
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Based on the experimental and DFT calculation results, here for the first time we built preferential adsorption sites for nitroarenes by modification of the supported Cu catalysts surface with 1,10-phenathroline (1,10-phen), by which the yield of aniline via reduction of nitroarene is enhanced three times. Moreover, a macromolecular layer was in-situ generated on supported Cu catalysts to form a stable macromolecule modified supported Cu catalyst, i.e., CuAlOx-M. By applying the CuAlOx-M, a wide variety of nitroarene substrates react smoothly to afford the desired products in up to > 99% yield with > 99% selectivity. The method tolerates a variety of functional groups, including halides, ketone, amide, and C = C bond moieties. The excellent catalytic performance of the CuAlOx-M can be attributed to that the 1,10-phen modification benefits the preferential adsorption of nitrobenzene and slightly weakens adsorption of aniline on the supported nano-Cu surface.
- Dai, Xingchao,He, Dongcheng,Li, Teng,Shi, Feng,Wang, Hongli,Wang, Tao,Wang, Xinzhi
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- The Solvent Effect on the Electro-oxidation of 1,4-Phenylenediamine. The Influence of the Solvent Reorientation Dynamics on the One-electron Transfer Rate
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The one-electron electro-oxidation of 1,4-phenylenediamine to the corresponding radical cation has been studied by cyclic voltammetry at a Pt electrode in perchlorate solutions in a wide range of aprotic and hydrogenbonded solvents.A linear relationship between the redox potential of this system and the donor number of a given solvent has been found.It has been shown that the dynamics of solvent reorientation strongly affects the heterogeneous electron transfer rate in the studied case: an almost linear relationship between the standard rate constant and the reciprocal of the longitudinal dielectric relaxation time of a given solvent has been found.It has been suggested that the solvent dynamics affects the rate of the analogous homogeneous electron-transfer reaction.
- Opallo, Marcin
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- Visible-light-induced photocatalytic hydrogenation of 4-nitroaniline over In2S3 photocatalyst in water
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Photocatalytic hydrogenation of 4-nitroaniline over the In 2S3 photocatalyst was investigated in water under visible light irradiation (λ ≥ 420 nm). After 90 min of visible light irradiation, 100% of 4-nitroaniline could be reduced t
- Wu, Weiming,Lin, Rui,Shen, Lijuan,Liang, Ruowen,Yuan, Rusheng,Wu, Ling
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- Application of silica-supported Fe–Cu nanoparticles in the selective hydrogenation of p-dinitrobenzene to p-phenylenediamine
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Supported bimetallic Fe–Cu/SiO2 materials are synthesized, and their catalytic activity in hydrogenation of dinitrobenzene to phenylenediamine at 145–180°С and 1.3 MPa hydrogen pressure is studied for the first time. The best results (89% selectivity toward p-phenylenediamine at complete conversion of p-dinitrobenzene) are obtained for the sample synthesized via co-deposition with subsequent calcination at 300°С. The sample contains 7% iron and 3% copper. The formation of separate phases of metal oxides (for the catalysts prepared by impregnation) and mixed bimetallic oxide phases (in case of co-deposition procedure) in calcined samples is revealed via thermoprogrammed reduction with hydrogen.
- Shesterkina,Shuvalova,Kirichenko,Strelkova,Nissenbaum,Kapustin,Kustov
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- Preparation and characterization of Ni/mZSM-5 zeolite with a hierarchical pore structure by using KIT-6 as silica template: An efficient bi-functional catalyst for the reduction of nitro aromatic compounds
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Ni/mZSM-5 and Ni/H-mZSM-5 were synthesized as hierarchical (micro/meso porous) ZSM-5 zeolites by an indirect template method for the first time. The resulting zeolite materials exhibited significantly enhanced diffusional properties in comparison to purely microporous zeolite materials. The structural and morphological characterization of the prepared catalysts was investigated using XRD, BET, atomic absorption spectroscopy, FT-IR, 27Al-MAS NMR, SEM, TEM, XPS and DRS-UV techniques. These hierarchical zeolites were used as acid-metal bi-functional heterogeneous catalysts for hydride transfer in the reduction of nitro aromatic compounds. In these reactions, NaBH4 was used as a reducing agent. Excellent yields at room temperature and very short reaction times in aqueous media conditions were obtained. Reusability experiments showed the excellent stability of Ni/mZSM-5 and Ni/H-mMZSM-5 and the catalysts could be reused 7 times without much loss of activity in reduction of nitro aromatic compounds. Surprisingly, the acid form of Ni/H-mZSM-5 showed much higher activity than that of Ni/mZSM-5. High yield, short reaction time, green solvent (water), room temperature, no by-product, the easy reusability of catalysts and the low amounts of catalyst required are some of the advantages of these catalysts.
- Mazaheri, Omid,Kalbasi, Roozbeh Javad
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- A simple and convenient method for the reduction of nitroarenes
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A variety of nitroarenes such as simple, electron rich and electron poor were reduced on A12O3 support in presence of sodium hydrogen sulphide under microwave condition to give the corresponding aromatic amines in high yields. It is found that the substituents at different positions on nitrobenzene have no influence except 2d on the rate of reaction and yields of product.
- Ravi Kanth,Venkat Reddy,Rama Rao,Maitraie,Narsaiah,Shanthan Rao
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- Supported polymer magnets with high catalytic performance in the green reduction of nitroaromatic compounds
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Magnetic Fe3O4 nanoparticles (MNPs) were prepared by a simple co-precipitation method using molar ratios of Fe2+:Fe3+ = 1:2 in ammonia solution, and subsequently were modified with tetraethyl orthosilicate (TEOS
- Safari,Gandomi-Ravandi,Haghighi
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- Self-Assembled Magnetic Gold Catalysts from Dual-Functional Boron Clusters
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A new class of core–shell magnetic gold nanocomposites is prepared in a raspberry-like fashion by the controlled supramolecular host–guest assembly of γ-cyclodextrins (γ-CDs) and boron clusters. In this work, Cs2[closo-B12H12], a fundamental boron cluster, can play a dual role in the preparation of highly monodispersed Au nanoparticles and in the immobilization of Au nanoparticles on the γ-CDs@Fe3O4 surface as an effective anchor. This facile and spontaneous supramolecular strategy allows for the control of the size and composition of the highly stable gold composites. Furthermore, the obtained AuNPs@Fe3O4 composites exhibit an excellent catalytic activity and recyclability for the selective reduction of nitroaromatics to their corresponding aniline compounds, and the fastest reaction can be achieved within 20 s with a high conversion and selectivity at room temperature, which is better than that obtained previously in studies on metal nanoparticle composites as catalysts.
- Qi, Bin,Wu, Chenchen,Li, Xin,Wang, Dan,Sun, Liang,Chen, Bo,Liu, Wenjing,Zhang, Haibo,Zhou, Xiaohai
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- Starch functionalized creatine for stabilization of gold nanoparticles: Efficient heterogeneous catalyst for the reduction of nitroarenes
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Selective reduction of nitroaromatic pollutants into amines with recoverable and reusable heterogeneous catalysts is highly desirable. Herein, we prepared and characterized an efficient novel catalyst comprising 4 nm size Au nanoparticles supported on creatine modified starch. Using this catalyst, efficient reduction of nitroarenes into amines at room temperature in aqueous media was achieved. The presence of creatine in the structure of the catalyst plays important role in amount of Au loading, efficiency of the catalyst, recycling times, and leaching of Au compared to starch supported Au without creatine.
- Gholinejad, Mohammad,Dasvarz, Neda,Shojafar, Mohammad,Sansano, José M.
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- Hexafluoro-2-propanol Promotes para-Selective C–H Amination of Free Anilines with Azodicarboxylates
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An effective, mild, and clean method for the C–H amination of free anilines with azodicarboxylates in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) without the need for any additional catalysts or reagents was developed. The reaction was found to be highly regioselective and provided a series of p-aminophenylhydrazine derivatives in excellent yields. Moreover, compatibility with a free amino group makes this protocol an attractive strategy in synthetic chemistry.
- Tang, Ren-Jin,Milcent, Thierry,Crousse, Benoit
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- Detection and determination of aromatic amines as products of reductive splitting from selected azo dyes
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The current environment-friendly regulations concerning textile products ban the marketing of textiles dyed with azo dyes capable of reductively splitting carcinogenic aromatic amines. The study analyzes seven azo dyes whose chemical structure determines various quantities of splitting aromatic amines, such as benzidine. For tests, seven commercially available azo dyes with aromatic amines in their structure were selected. These included two hazardous dyes: Acid Red 85 and Direct Blue 6, both capable of reductively splitting carcinogenic benzidine. Of the remaining five azo dyes, three - Ponceau SS, Sudan II, and Disperse Yellow 7 - are capable of splitting p-phenylenediamine and aniline, while Mordant Orange 1 and Disperse Orange 3 can split only p-phenylenediamine. For Acid Red 85 and Direct Blue 6, the quantity of benzidine split from them was analyzed, depending on the conditions of the reduction process (e.g., in the HPLC method, 104 g/kg of dye for reduction in NaOH, and 41 g/kg of dye for reduction in acetate buffer). The spectrophotometric method proved useful for preliminary analysis of amine content in examined samples. Spectrophotometric analysis may be used to determine the total content of amines counted as aniline. A full qualitative and quantitative analysis of amines released from azo dyes is possible using high-performance liquid chromatography (HPLC).
- Pielesz,Baranowska,Rybak,Wlochowicz
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- Comparison between Heterogeneous and Homogeneous Electron Transfer in p-Phenylenediamine Systems
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The one-electron oxidation of selected p-phenylendiamines to form the corresponding radical cations has been studied at a Pt electrode in dimethylformamide and acetonitrile solutions containing 0.1 mol dm-3 NaClO4.The standard redox potentials, the diffusion coefficients and the standard rate constants have been evaluated in the range between room temperature and the melting point of the respective solvent using cyclic valtammetry.It has been shown that the dynamics of solvent reorientation affects the heterogeneous electron-transfer rate, as opposed to the homogeneous process.The free energies of activation are much greater in the heterogeneous than in the homogeneous case.Both results are explained by the different shape of the activated complexes, consisting of one or two ellipsoidal molecules.
- Kapturkiewicz, Andrzej,Jaenicke, Walther
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- Indium(III)-Catalyzed Reduction of Nitrobenzenes to Anilines: Scope and Limitations
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We have demonstrated that a combination of indium(III) iodide and 1,1,3,3-tetramethyldisiloxane (TMDS) effectively catalyzes the chemoselective reduction of nitrobenzenes with a variety of functional groups (halogens, alkyl, alkoxy, hydroxy, ester, amino, amide, cyanide, thiol, and an alkene moiety), producing the corresponding aniline derivatives.
- Sakai, Norio,Asama, Shun,Konakahara, Takeo,Ogiwara, Yohei
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- Zeolite-Encaged Single-Atom Rhodium Catalysts: Highly-Efficient Hydrogen Generation and Shape-Selective Tandem Hydrogenation of Nitroarenes
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Single-atom catalysts are emerging as a new frontier in heterogeneous catalysis because of their maximum atom utilization efficiency, but they usually suffer from inferior stability. Herein, we synthesized single-atom Rh catalysts embedded in MFI-type zeolites under hydrothermal conditions and subsequent ligand-protected direct H2 reduction. Cs-corrected scanning transmission electron microscopy and extended X-ray absorption analyses revealed that single Rh atoms were encapsulated within 5-membered rings and stabilized by zeolite framework oxygen atoms. The resultant catalysts exhibited excellent H2 generation rates from ammonia borane (AB) hydrolysis, up to 699 min?1 at 298 K, representing the top level among heterogeneous catalysts for AB hydrolysis. The catalysts also showed superior catalytic performance in shape-selective tandem hydrogenation of various nitroarenes by coupling with AB hydrolysis, giving >99 % yield of corresponding amine products.
- Sun, Qiming,Wang, Ning,Zhang, Tianjun,Bai, Risheng,Mayoral, Alvaro,Zhang, Peng,Zhang, Qinghong,Terasaki, Osamu,Yu, Jihong
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- Peculiarities of azobenzene catalytic hydrogenation in 2-propanol aqueous solutions with acid or base additives
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It is shown experimentally that the hydrogenation of azobenzenes over a nickel skeleton catalyst in 2-propanol aqueous solutions proceeds selectively with the formation of aniline. It is pointed out that during the reaction, considerable participation of hydrogen bonded with active centers of a catalyst surface was observed. The competitive character of adsorption between the initial azo compound and aniline formed as a result of reaction is established. It is concluded that purposeful change of the azo group hydrogenation rate is possible by introducing acid or base additives into 2-propanol aqueous solution.
- Lefedova,Kha, Nguen Tkhi Tkhu,Komarov,Budanov
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- Cu nanoparticles: a highly efficient non-noble metal catalyst for rapid reduction of nitro compounds to amines with NaBH4 in water
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The purely aqueous-phase reduction of a wide range of nitro compounds to the corresponding amines has been carried out with NaBH4 in the presence of inexpensive Cu nanoparticles as catalyst. The reactions were taken place in water (80?°C) within 4–15?min to give amines in high to excellent yields.
- Zeynizadeh, Behzad,Zabihzadeh, Mehdi,Shokri, Zahra
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- Bio-waste chitosan-derived N-doped CNT-supported Ni nanoparticles for selective hydrogenation of nitroarenes
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In this study, a facile method for the synthesis of leach proof and earth-abundant non-noble Ni nanoparticles on N-doped carbon nanotubes is reported. The catalyst was synthesized by an impregnation-carbonization method, wherein a Ni-chitosan complex upon carbonization in a 5% H2/N2 atmosphere at 800 °C yielded Ni-containing N-doped CNTs. Chitosan served as a single source of carbon and nitrogen, and the nanotube growth was facilitated by the in situ formed Ni nanoparticles. The nanocatalyst was thoroughly characterized by several techniques; elemental mapping by SEM and TEM analysis confirmed the uniform distribution of Ni nanoparticles on the surface of N-doped CNTs with an average size in the range of 10-15 nm. The catalyst efficiently reduced a variety of nitroarenes (>99%) into their corresponding amines at a moderate pressure (5 bar) and a comparatively lower temperature (80 °C). Furthermore, the easy recovery of the catalyst using an external magnetic field along with high activity and easy recyclability makes the protocol eco-friendly.
- Advani, Jacky H.,Bajaj, Hari C.,Biradar, Ankush V.,Gawande, Manoj B.,Naikwadi, Dhanaji R.,Ravi, Krishnan
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- DFNS/PEI/Cu Nanocatalyst for Reduction of Nitro-aromatic Compounds
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Abstract: Nitro-aromatic pollution in industrial waste streams threat wellbeing of water resources. This study investigates the performance of a copper-based nano catalyst to reduce nitro-aromatic compounds in aqueous solution. Anchoring Cu NPs within the nano spaces of a fibrous silicate with high surface area, and simple accessibility of active sites were successfully established by a facile approach to produce a novel nanocatalyst (DFNS/PEI/Cu). DFNS displayed different properties such as dandelion-like shape, high surface area, and simple availability of active sites. Immobilization of the Cu NPs on DFNS nanospheres not only prevented their aggregation, but also considerably improved the availability of the catalytic active sites. The DFNS/PEI/Cu nanocatalyst demonstrated great catalytic activities for the reduction of nitro compounds under green conditions. Our findings show fibrous DFNS and Cu NPs as a helpful platform for the fabrication of noble metal-based affordable nanocatalyst for many catalytic applications. Graphic Abstract: DFNS/PEI/Cu nanocatalyst as a new adsorbents for the reduction of nitro compounds[Figure not available: see fulltext.]
- Moradi, Marjan,Rastakhiz, Nahid,Ghaedi, Mehrorang,Zhiani, Rahele
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- Facile reduction of aromatic nitro compounds to aromatic amines catalysed by support-free nanoporous silver
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Nanoporous silver was used as the catalyst for the reduction of aromatic nitro compounds even in the presence of some sensitive functional groups under mild conditions with excellent yields. A reduced amount of NaBH4 was used. The reaction kine
- Li, Zhiwen,Xu, Xiaohong,Jiang, Xiaojian,Li, Yingchun,Yu, Zhixin,Zhang, Xiaomei
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- Synergistic action of flavin containing NADH dependant azoreductase and cytochrome P450 monooxygenase in azoaromatic mineralization
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An alkaliphilic strain Bacillus lentus BI377 was isolated from contaminated soil of the textile area of Solapur, India. The strain was able to degrade almost 98% of recalcitrant azoic compounds by a mutually regulated process of azoreductase and a monooxygenase system. An enzyme activity study and a periodical carbon monoxide (CO) binding spectra study on a UV-visible spectrophotometer revealed that the intermediate amines formed by typical azoreduction (NN cleavage), subsequently underwent hydroxylation by the cytochrome P450 monooxygenase (CYP450) system. Azoreductase was purified by chromatographic techniques and characterization by MALDI-TOF substantiated its identity as FMN containing NADH dependent azoreductase of 32 kDa in size. Surprisingly, purified azoreductase showed the highest activity at 80 °C and pH 8.0. An increase in the activity of superoxide dismutase after decolorization confirmed the signature of oxidative stress and its involvement in the dismutation of reactive metabolites. Intermediate metabolite analysis by HPLC, GC-MS and FTIR and the removal of total organic carbon (TOC) suggested the azoaromatics' degradation leads to mineralization via a TCA cycle.
- Oturkar, Chetan C.,Othman, Munif A.,Kulkarni, Mahesh,Madamwar, Datta,Gawai, Kachru R.
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- Kinetics of the hydrogenation of 2-chloro-4-nitroaniline over skeletal nickel and supported palladium catalysts in an aqueous solution of 2-propanol
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The kinetics of the liquid-phase hydrogenation of 2-chloro-4-nitroaniline in an aqueous solution of 2-propanol over skeletal nickel and supported palladium catalysts is studied. The selectivity of the reaction with respect to 2-chloro-1,4-phenylenediamine is determined. It is found that samples of supported palladium catalysts differ with respect to the amount of the active component and the nature of the support. Some of their structural characteristics are provided.
- Krasnov,Latypova,Lefedova,Sharonov, N. Yu.
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- Generation and characterization of palladium nanocatalyst anchored on a novel polyazomethine support: Application in highly efficient and quick catalytic reduction of environmental contaminant nitroarenes
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Removal of toxic nitroarenes, which threaten all living organisms and environment, from wastewaters has been an important and prior issue. Therefore, the focus of the present study was to fabricate an effective, fast, reusable, and easily recoverable heterogeneous Pd nanoparticles (Pd NPs) supported on a novel polyazomethine having phenol group (Pd NPs? P(3-M-4-PAP)) for removal of several hazardous nitroarenes by catalytic reduction from water. Firstly, a novel polyazomethine featuring phenol group was prepared as a stabilizer and then, Pd NPs were anchored on it. Characterizations of the materials were performed by XRD, UV–Vis, FTIR, 1H-NMR, TGA, FE-SEM, EDS and TEM techniques. The obtained TEM analysis results showed that the size of Pd NPs was about 50 nm. Then, catalytic ability of Pd NPs?P(3-M-4-PAP) was investigated in reduction of harmful nitroarenes to useful aniline derivatives in water. Catalytic tests revealed that Pd NPs?P(3-M-4-PAP) had outstanding catalytic efficiency against reduction of different nitroarenes by giving excellent yields (up to 98%), in very short time (between 22s and 70s) with 2 mg nanocatalyst. Moreover, performed reusability test results demonstrated that the Pd NPs?P(3-M-4-PAP) could be recurrently reusable and easily recoverable.
- Y?lmaz Baran, Nuray
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- Sustainable and recyclable palladium nanoparticles–catalyzed reduction of nitroaromatics in water/glycerol at room temperature
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Palladium nanoparticles with unique catalytic activity and high stability are synthesized. These nanoparticles exhibit excellent catalytic reduction activity for nitroaromatics in green solvents in the presence of H2 at ambient pressure and temperature. The prominent advantages of this nanotechnology include low consumption of catalyst, excellent chemoselectivity, high reusability of the catalyst, and environmentally green solvents.
- Chen, Jin,Dai, Bencai,Liu, Changchun,Shen, Zhihao,Zhao, Yongde,Zhou, Yang
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- Electrochemical amination: IX.1 effectiveness of the process
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Electrochemical amination of aromatic compounds with hydroxylamine in sulfuric acid in the presence of transition metal ions occurs by a chain mechanism. Electrolysis of the system Ti(IV)-NH2OH-C6H6 in 11 M H2SO4 and 5 M CH3COOH leads to formation of aniline and isomeric phenylenediamines with a total current yield of 137%. The role of acetic acid in the electrochemical process is not limited to aiding in solution of the aromatic compound. Acetic acid affects the mechanism of amination and can serve as one of the factors controlling the relative rate and selectivity of substitution.
- Lisitsyn,Makarova,Kargin
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- Immobilized iron oxide nanoparticles as stable and reusable catalysts for hydrazine-mediated nitro reductions in continuous flow
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An experimentally easy to perform method for the generation of alumina-supported Fe3O4 nanoparticles [(6±1)nm size, 0.67 wt%]and the use of this material in hydrazine-mediated heterogeneously catalyzed reductions of nitroarenes to anilines under batch and continuous-flow conditions is presented. The bench-stable, reusable nano-Fe3O4@Al2O3 catalyst can selectively reduce functionalized nitroarenes at 1 mol% catalyst loading by using a 20 mol% excess of hydrazine hydrate in an elevated temperature regime (150°C, reaction time 2-6 min in batch). For continuous-flow processing, the catalyst material is packed into dedicated cartridges and used in a commercially available high-temperature/-pressure flow device. In continuous mode, reaction times can be reduced to less than 1 min at 150°C (30 bar back pressure) in a highly intensified process. The nano-Fe3O4@Al2O3 catalyst demonstrated stable reduction of nitrobenzene (0.5 m in MeOH) for more than 10 h on stream at a productivity of 30mmolh-1 (0.72 mol per day). Importantly, virtually no leaching of the catalytically active material could be observed by inductively coupled plasma MS monitoring.
- Moghaddam, Mojtaba Mirhosseini,Pieber, Bartholom?us,Glasnov, Toma,Kappe, C. Oliver
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- Flowerlike Bi2S3 microspheres: Facile synthesis and application in the catalytic reduction of 4-nitroaniline
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Flowerlike Bi2S3 microspheres have been successfully synthesized via a facile wet chemical route in air at 110 °C for 10 min, employing bismuth nitrate and thiourea in a molar ratio of 1:2 as the starting reactants, ethylene glycol a
- Guo, Fan,Ni, Yonghong,Ma, Yue,Xiang, Nannan,Liu, Chang
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- The Anodic Oxidation of 1,4-Diaminobenzene: an Electron Spin Resonance and Electrochemical Study
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The electrochemical e.s.r. of 1,4-diaminobenzene, 1,4-diamino-2-chlorobenzene, and 1,4-diamino-2-methylbenzene has been studied in aqueous methanol using an apparatus in which a tube electrode is linked to the e.s.r. cavity.Laminar flow transports species from the electrode into the cavity.The distribution of species in the cavity can be described theoretically and from the variation of e.s.r. signal with current, flow rate, concentration, and pH the protonation and kinetic stability of the 1,4-diaminobenzene cation radical is established.From the electrochemistry, the protonation of the unstable benzoquinone di-imide is deduced.The kinetics and the mechanism of its substitution reaction with water leading to benzoquinone are deduced from the behaviour of the e.s.r. signal from the radical cation with which the benzoquinone di-imide is in equilibrium.
- Albery, W. John,Compton, Richard G.,Kerr, Ian S.
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- Palladium Nanoparticles on a Creatine-Modified Bentonite Support: An Efficient and Sustainable Catalyst for Nitroarene Reduction
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Creatine as the nitrogen-rich, green and cheap compound is used for modification of natural bentonite and the resulting material is employed for the stabilization of Palladium nanoparticles having an average diameter of 3 nm. This new material bento-crt@Pd is characterized using different techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), solid state UV-vis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and energy-dispersive X-ray spectroscopy (EDX). This green catalyst promotes efficient reduction of aromatic nitro compounds in aqueous media. By using this catalyst nitroarenes having electron donating as well as electron withdrawing groups were reduced efficiently to their corresponding amines at room temperature. The catalyst can be recycled seven times and the reused catalyst was characterized by TEM and XPS.
- Gholinejad, Mohammad,Rasouli, Zahra,Najera, Carmen,Sansano, José M.
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- Unprotected and interconnected Ru0 nano-chain networks: Advantages of unprotected surfaces in catalysis and electrocatalysis
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Seedless, surfactantless and support-free unprotected, metallic, interconnected nano-chain networks of ruthenium nanoparticles (NPs) were successfully synthesized via the reduction of ruthenium(iii) chloride (RuCl3) with sodium borohydride (NaBH4) at three different temperatures, viz. 30 °C, 45 °C and 60 °C. The molar ratio of RuCl3 solution and borohydride was optimized to be 1:1.5 to produce stable colloids with the optimum final solution pH of 9.7 ± 0.2. Average diameters of the interconnected nano-chain networks prepared at 30 °C (Ru-30), 45 °C (Ru-45) and 60 °C (Ru-60) were 3.5 ± 0.5 nm, 3.0 ± 0.2 nm and 2.6 ± 0.2 nm respectively. The morphology and composition dependent catalytic and electrocatalytic activities of these unprotected Ru nano-chain networks (Ru-30, Ru-45 and Ru-60) were studied in detail. The catalysis study was performed by investigating the transfer hydrogenation of several substituted aromatic nitro compounds. It was observed that Ru-60 was relatively more active compared to Ru-30 and Ru-45, which was reflected in their rate constant values. The electrocatalytic activities of Ru-30, Ru-45 and Ru-60 were screened for anodic water splitting in alkaline medium (0.1 M NaOH) and it was found that all of them showed almost the same activity which required an over-voltage of 308 ± 2 mV to obtain an anodic current density of 10 mA cm-2. The catalytic and electrocatalytic performances of these unprotected Ru0 networks were compared with Ru0 nanomaterials prepared under similar conditions with three different surfactants, viz. CTAB, SDS and TX-100, which revealed that unprotected Ru0 networks are better catalysts than those stabilized with surfactants. The superior catalytic and electrocatalytic performance is due to the availability of unprotected Ru0 surfaces. The present route may provide a new possibility of synthesizing other surfactant-free, unprotected metal colloids for enhanced catalytic and electrocatalytic applications.
- Anantharaj,Jayachandran,Kundu, Subrata
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- Synthesis and characterization of Ni nanoparticles incorporated into hyperbranched polyamidoamine-polyvinylamine/SBA-15 catalyst for simple reduction of nitro aromatic compounds
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In this study, hyperbranched polyamidoamine (PAMAM) was grown up onto the surface of polyvinyl amine-functionalized SBA-15 (PVAm/SBA-15) by a divergent method, without using organosilane precursors. Because of the surface modification of the PVAm/SBA-15 w
- Kalbasi, Roozbeh Javad,Zamani, Farzad
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- Binuclear half-sandwich ruthenium(II) Schiff base complexes: Synthesis, characterization, DFT study and catalytic activity for the reduction of nitroarenes
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The binuclear ruthenium(II) p-cymene complexes containing Schiff base ligands of general composition [(Ru(p-cymene)Cl)2L1-6] (1-6) have been synthesized. The complexes were characterized by analytical and spectral (FT?IR, UV–Vis & 1H NMR) methods. The molecular structure of the representative complex [(Ru(p-cymene)Cl)2(L6)] (6) was determined by single-crystal X-ray diffraction and density functional theory (DFT) calculations. Further, these half-sandwich ruthenium complexes are active catalysts for the mild hydrogenation of nitroarenes to aromatic anilines in the presence of NaBH4 in ethanol. The most efficient catalyst 6, was found be compatible with nitroarenes of various functional groups.
- Nandhini, Raja,Krishnamoorthy, Bellie Sundaram,Venkatachalam, Galmari
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- Nanocrystalline magnesium oxide-stabilized palladium(0): An efficient and reusable catalyst for selective reduction of nitro compounds
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An efficient, mild and selective synthesis of aromatic and aliphatic amines from the corresponding nitro compounds has been realized by using a ligand-free heterogeneous nanocrystalline magnesium oxide-stabilized palladium(0) catalyst, employing molecular hydrogen as the reductant. The catalyst is recovered quantitatively by simple filtration and was reused for several cycles with consistent activity.
- Kantam, M. Lakshmi,Chakravarti, Rajashree,Pal, Ujjwal,Sreedhar,Bhargava, Suresh
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- Surface Roughness Effects of Pd-loaded Magnetic Microspheres on Reduction Kinetics of Nitroaromatics
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Metal nanoparticles decoration on magnetically active semiconductor materials is a common strategy to improve the colloidal stability, catalyst harvesting, and reuse. In this study, a surfactant-free solvothermal method followed by a heat treatment to pre
- An, Seonghwi,Manivannan, Shanmugam,Viji, Mayavan,Shim, Min Suk,Hwang, Byeong Hee,Kim, Kyuwon
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- Hydrogenation of Substituted Benzenes Containing Nitro and Azo Groups over Skeletal Nickel in Aqueous Solutions of 2-Propanol
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Abstract: An analysis is made of the kinetic characteristics of the hydrogenation of 4-nitro- and 2-nitro-2'-hydroxy-5'-methylazobenzenes, 4-nitroaniline and 4-aminoazobenzene over skeletal nickel in neutral azeotropic 2-propanol–water mixture and in the same solvent in the presence of acetic acid or sodium hydroxide. It is found that the selectivity of the hydrogenation of these isomers to the intermediate products depends on the composition and nature of the solvent, and is determined by the rate of reactive group conversion. Compared to the process in the presence of sodium hydroxide, which suppresses the route leading to the predominant hydrogenation of the nitro group, the contribution from the transformation of azo group is considerably greater in the hydrogenation of 4-nitro-2'-hydroxy-5'-methylazobenzene in the presence of acetic acid. Adding a base to the solvent during the hydrogenation of 2-nitro-2'-hydroxy-5'-methylazobenzene accelerates the rate of nitro group conversion and the intramolecular cyclization of the intermediate compound, increasing the selectivity towards the products containing the benzotriazole cycle (particularly 2-(2-hydroxy-5-methylphenyl)benzotriazole-N-oxide). The almost linear correlation between the selectivity of the catalytic hydrogenation of isomers of nitro-2'-hydroxy-5'-methylazobenzene and the kinetic characteristics of the hydrogenation of nitro and azo groups in compounds containing a single reactive substituent at different values of medium’s pH is estimated.
- An’, Khoang,Belova, A. V.,Lefedova, O. V.,Nemtseva, M. P.
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- Highly Efficient Pt-Catalyst Supported on Mesoporous Ceria-Zirconia Oxide for Hydrogenation of Nitroaromatic Compounds to Anilines
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Abstract: In this work, we have prepared a new catalytic system based on highly dispersed Pt nanoparticles supported on mesoporous ceria-zirconia oxide. The unique ability of the synthesized catalyst to activate hydrogen in the temperature range from –50 to 25°C allows us to provide selective hydrogenation of nitro-aromatic compounds to anilines at room temperature and atmospheric pressure of H2.
- Redina,Vikanova
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- METHOD FOR PRODUCING AMINO AROMATIC COMPOUND
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To provide a novel method for producing an amino aromatic compound.SOLUTION: A method for producing a compound (B) having at least one amino group on an aromatic ring, includes at least a step in which a compound (A) at least having an aromatic ring and one group represented by -CR=CH2 [R is a hydrogen atom or a C1-3 alkyl group] on the aromatic ring is reacted with sodium azide in the presence of acid.SELECTED DRAWING: None
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Paragraph 0040-0045
(2021/03/03)
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- Method for preparing amine through catalytic reduction of nitro compound by cyclic (alkyl) (amino) carbene chromium complex
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The cyclic (alkyl) (amino) carbene chromium complex is prepared from corresponding ligand salt, alkali and CrCl3 and used for catalyzing pinacol borane to reduce nitro compounds in an ether solvent under mild conditions to generate corresponding amine. The method for preparing amine has the advantages of cheap and accessible raw materials, mild reaction conditions, wide substrate application range, high selectivity and the like, and is simple to operate.
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Paragraph 0015
(2021/04/17)
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- Yeast supported gold nanoparticles: an efficient catalyst for the synthesis of commercially important aryl amines
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Candida parapsilosisATCC 7330 supported gold nanoparticles (CpGNP), prepared by a simple and green method can selectively reduce nitroarenes and substituted nitroarenes with different functional groups like halides (-F, -Cl, -Br), olefins, esters and nitriles using sodium borohydride. The product aryl amines which are useful for the preparation of pharmaceuticals, polymers and agrochemicals were obtained in good yields (up to >95%) using CpGNP catalyst under mild conditions. The catalyst showed high recyclability (≥10 cycles) and is a robust free flowing powder, stored and used after eight months without any loss in catalytic activity.
- Krishnan, Saravanan,Patel, Paresh N.,Balasubramanian, Kalpattu K.,Chadha, Anju
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supporting information
p. 1915 - 1923
(2021/02/06)
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- Porous polymeric ligand promoted copper-catalyzed C-N coupling of (hetero)aryl chlorides under visible-light irradiation
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A porous polymeric ligand (PPL) has been synthesized and complexed with copper to generate a heterogeneous catalyst (Cu@PPL) that has facilitated the efficient C-N coupling with various (hetero)aryl chlorides under mild conditions of visible-light irradiation at 80 °C (58 examples, up to 99% yields). This method could be applied to both aqueous ammonia and substituted amines, and is compatible to a variety of functional groups and heterocycles, as well as allows tandem C-N couplings with conjunctive dihalides. Furthermore, the heterogeneous characteristic of Cu@PPL has enabled a straightforward catalyst separation in multiple times of recycling with negligible catalytic efficiency loss by simple filtration, affording reaction mixtures containing less than 1 ppm of Cu residue. [Figure not available: see fulltext.]
- Wang, Erfei,Chen, Kaixuan,Chen, Yinan,Zhang, Jiawei,Lin, Xinrong,Chen, Mao
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- Preparation method of P-phenylenediamine
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The invention discloses a preparation method of p-phenylenediamine, which comprises the step of reacting p-dichlorobenzene with ammonia in the presence of a copper catalyst and a ligand to obtain p-phenylenediamine. According to the method, the catalyst ligand is added into a reaction system, so that the catalyst activity is improved, the reaction conditions are milder, the reaction efficiency ishigh, and the method is suitable for industrial production.
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Paragraph 0018-0029
(2021/01/24)
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- UiO-66/btb/Pd as a stable catalyst reduction of 4-nitrophenol into 4-aminophenol
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In order to synthesize highly sparse nanoparticles, UiO-66-NH2 can be utilized as an appropriate support. It has great surface area, which is functionalized by 1,3-bis(dimethylthiocarbamoyloxy)benzene compounds that can act as the powerful performers, hence, the Pd (II) is a complex without aggregate over the UiO-66-NH2 microspheres structures (UiO-66/btb/Pd). Nitro-aromatic pollution in industrial waste streams threat wellbeing of water resources. The produced UiO-66/btb/Pd nanocatalyst showed appropriate catalytic activity for reduce nitro-aromatic compounds in aqueous solution. XRD, EDS, SEM, FT-IR, and TEM were utilized for characterizing the nanostructures UiO-66/btb/Pd.
- Kiani, Zahra,Zhiani, Rahele,Khosroyar, Susan,Motavalizadehkakhky, Alireza,Hosseiny, Malihesadat
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- Highly porous copper-supported magnetic nanocatalysts: made of volcanic pumice textured by cellulose and applied for the reduction of nitrobenzene derivatives
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Herein, a novel designed heterogeneous catalytic system constructed of volcanic pumice magnetic particles (VPMPs), cellulose (CLS) as a natural polymeric matrix, and copper nanoparticles (Cu NPs) is presented. Also, to enhance the inherent magnetic property of VPMP, iron oxide (Fe3O4) nanoparticles have been prepared and incorporated in the structureviaanin situprocess. As its first and foremost excellent property, the designed composite is in great accordance with green chemistry principles because it contains natural ingredients. Another brilliant point in the architecture of the designed composite is the noticeable porosity of VPMP as the core of the composite structure (surface area: 84.473 m2g?1). This great porosity leads to the use of a small amount (0.05 g) of the particles for catalytic purposes. However, the main characterization methods, such as Fourier-transform infrared and energy-dispersive X-ray spectroscopy, thermogravimetric analysis, and electron microscopy, revealed that the spherical metallic particles (Fe and Cu oxides) were successfully distributed onto the surface of the VPMP and CLS matrices. Further, vibrating-sample magnetometer analysis confirmed the enhancement of the magnetic property (1.5 emu g?1) of the composite through the addition of Fe3O4nanoparticles. Further, the prepared (Fe3O4@VPMP/CLS-Cu) nanocomposite has been applied to facilitate the reduction reaction of hazardous nitrobenzene derivatives (NBDs) to their aniline analogs, with 98% conversion efficiency in eight minutes under mild conditions. Moreover, the good reusability of the catalytic system has been verified after recycling it ten times without any significant decrease in the performance.
- Fazeli, Atefeh,Maleki, Ali,Qazi, Fateme Sadat,Saeidirad, Mahdi,Shalan, Ahmed Esmail,Taheri-Ledari, Reza
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p. 25284 - 25295
(2021/08/05)
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- Magnetically‐recoverable Schiff base complex of Pd(II) immobilized on Fe3O4@SiO2 nanoparticles: an efficient catalyst for the reduction of aromatic nitro compounds to aniline derivatives
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Fe3O4@SiO2/Schiff base/Pd(II) is reported as a magnetically recoverable heterogeneous catalyst for the chemoselective reduction of aromatic nitro compounds to the corresponding amines through catalytic transfer hydrogenation (CTH). In this regard, a small amount of the nanocatalyst (0.52?mol% Pd) and hydrazine hydrate, showing safe characteristics and perfect ability as the hydrogen donor, were added to the nitro substrates. The experiments described the successful reduction of aromatic nitro compounds with good to excellent yields and short reaction times. The catalyst, due to its magnetic property, could be simply separated from the reaction mixture by a permanent magnet and reused in seven consecutive reactions without considerable loss in its activity. Moreover, the leaching of Pd was only 3.6% after the seventh run. Thus, the most striking feature of this method is to use a small amount of the magnetic nanocatalyst along with a cheap and safe hydrogen source to produce the important amine substances selectively, which makes the method economical, cheap, environmentally friendly, and simple. Graphic abstract: [Figure not available: see fulltext.]
- Azadi, Sedigheh,Esmaeilpour, Mohsen,Sardarian, Ali Reza
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p. 809 - 821
(2021/07/20)
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- Development of sustainable and efficient nanocatalyst based on polyoxometalate/nickel oxide nanocomposite: A simple and recyclable catalyst for reduction of nitroaromatic compounds
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In this paper, we report the synthesis and characterization of NiO@PolyMo nanocomposite. The newly synthesized nanocomposite was characterized by transmission electronmicroscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and powder X-ray diffraction (XRD). The particle sizes of the NiO@PolyMo nanocatalyst are in the range of 10–20 nm. Powder XRD patterns show that the phase of NiO@PolyMo remains unaltered even after the functionalization of NiO. The lattice fringes of d = 0.20 nm were observed, which correspond to the (111) plane of NiO phase. The newly synthesized material shows excellent catalytic performance and good selectivity for reduction of nitroarenes. The advantages of the present protocols are mild, and can be carried out using water as a solvent, which is an eco-friendly benign.
- Kurbah, Sunshine Dominic
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p. 1487 - 1495
(2021/04/22)
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- Chemoselective Hydrogenation of Nitroarenes Using an Air-Stable Base-Metal Catalyst
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The reduction of nitroarenes to anilines as well as azobenzenes to hydrazobenzenes using a single base-metal catalyst is reported. The hydrogenation reactions are performed with an air-and moisture-stable manganese catalyst and proceed under relatively mild reaction conditions. The transformation tolerates a broad range of functional groups, affording aniline derivatives and hydrazobenzenes in high yields. Mechanistic studies suggest that the reaction proceeds via a bifunctional activation involving metal-ligand cooperative catalysis.
- Zubar, Viktoriia,Dewanji, Abhishek,Rueping, Magnus
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supporting information
p. 2742 - 2747
(2021/05/05)
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- Activated Mont K10-Carbon supported Fe2O3: A versatile catalyst for hydration of nitriles to amides and reduction of nitro compounds to amines in aqueous media
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The iron oxide was successfully supported on activated clay/carbon through an experimentally viable protocol for both hydrations of nitrile to amide and reduction of nitro compounds to amines. The as-prepared catalyst has been extensively characterised by XPS, SEM-EDX, TEM, TGA, BET surface area measurements and powdered X-ray diffraction (PXRD). A wide variety of substrates could be converted to the desired products with good to excellent yields by using water as a green solvent for both the reactions. The catalyst was recyclable and reusable up to six consecutive cycles without compromising its catalytic proficiency. Graphical abstract: Activated Mont K10 carbon-supported Fe2O3 is a very efficient and versatile heterogeneous catalytic system for hydration of nitriles to amides and reduction of nitro compounds to amines and can be reused up to six consecutive cycles without significant loss in catalytic activity.[Figure not available: see fulltext.].
- Rahman, Taskia,Borah, Geetika,Gogoi, Pradip K
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- Synthesis of CoFe2O4@Pd/Activated carbon nanocomposite as a recoverable catalyst for the reduction of nitroarenes in water
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Efficient reduction of nitro compounds into amines is an important industrial transformation. So, it is a great deal to design new catalysts for efficient reduction of the nitro compounds especially in water. In this work, a new magnetic Pd/activated carbon nanocomposite (CoFe2O4@Pd/AC) was synthesized via metal-impregnation-pyrolysis method. The CoFe2O4@Pd/AC was fully characterized by FT-IR, PXRD, FESEM, TEM, VSM, EDX-mapping and BET techniques. The results showed that CoFe2O4@Pd/AC is a highly reactive and easily recoverable magnetic catalyst for the reduction of the nitro compounds by using NaBH4 in water. For instance, aniline was obtained in high yield (99%) after 75 ?min at 25 ?C by using just 6 ?mg of the catalyst. In addition, CoFe2O4@Pd/AC was recovered by a simple magnetic decantation and it exhibits stable activity and remains intact during the catalytic process with no significant loss in activity (8 cycles).
- Hamadi, Hosein,Kazeminezhad, Iraj,Mohammadian, Sara
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- Synthesis, Structure, and Catalytic Hydrogenation Activity of [NO]-Chelate Half-Sandwich Iridium Complexes with Schiff Base Ligands
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A series of N,O-coordinate iridium(III) complexes with a half-sandwich motif bearing Schiff base ligands for catalytic hydrogenation of nitro and carbonyl substrates have been synthesized. All iridium complexes showed efficient catalytic activity for the hydrogenation of ketones, aldehydes, and nitro-containing compounds using clean H2 as reducing reagent. The iridium catalyst displayed the highest TON values of 960 and 950 in the hydrogenation of carbonyl and nitro substrates, respectively. Various types of substrates with different substituted groups afforded corresponding products in excellent yields. All N,O-coordinate iridium(III) complexes 1-4 were well characterized by IR, NMR, HRMS, and elemental analysis. The molecular structure of complex 1 was further characterized by single-crystal X-ray determination.
- Lv, Wen-Rui,Li, Rong-Jian,Liu, Zhen-Jiang,Jin, Yan,Yao, Zi-Jian
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p. 8181 - 8188
(2021/05/26)
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- A Concise Route to Cyclic Amines from Nitroarenes and Ketoacids under Iron-Catalyzed Hydrosilylation Conditions
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Starting from nitroarenes, under hydrosilylation conditions, using a well-defined N-heterocyclic carbene iron(0) catalyst, (IMes)Fe(CO)4, the corresponding aniline derivatives were produced in 61–92% isolated yields. More impressively, a selective synthesis of cyclic amines such as pyrrolidines, piperidines and azepanes were conducted from levulinic acid, 1,5- and 1,6-keto acids, respectively. The sequential procedure proceeded under both visible light irradiation and thermal conditions with 20 examples in isolated yields up to 69%. (Figure presented.).
- Ammaiyappan, Yuvaraj,Darcel, Christophe,Tongdee, Satawat,Wu, Jiajun
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p. 3859 - 3865
(2021/07/12)
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- Pd nanoparticles/graphene quantum dot supported on chitosan as a new catalyst for the reduction of nitroarenes to arylamines
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A new heterogeneous catalyst was obtained by growing graphene quantum dots on chitosan and subsequent immobilization of Pd nanoparticles. The catalyst after characterization was used in the reduction of nitroarenes to the corresponding amines by NaBH4 as a weak reducing agent of nitro compounds. The catalyst exhibited excellent catalytic activity and selectivity under mild reaction conditions in water as a green solvent during 1?h. Additionally, the catalyst can be reused for five consecutive runs without any significant decrease in its activity and selectivity.
- Kalanpour, Nastaran,Nejati, Saeid,Keshipour, Sajjad
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p. 1243 - 1250
(2020/10/29)
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- Fabrication of magnetically separable ruthenium nanoparticles decorated on channelled silica microspheres: Efficient catalysts for chemoselective hydrogenation of nitroarenes
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Fe3O4-SiO2microspheres were synthesized by a three-step synthetic procedure involving silica coating, surface capping, and surface modification. These magnetic mesoporous microspheres were employed as sorbents for the incorporation of ultrasmall Ru nanoparticles (2-5 nm) followed by thermal aggregation of the microspheres for achieving better heterogeneity and low leaching. The Ru decorated Fe3O4-SiO2microspheres (Ru@Fe3O4-CSM) were applied as chemoselective catalysts to convert more than 20 substituted nitroarenes to corresponding amines with good-to-excellent conversion (77-99%) and selectivity (70-100%) under mild conditions; the catalyst can be magnetically recovered within a frame of 90s (recovery time-lapse) and reused up to 5 times without significant decrease in activity or selectivity. Magnetic hysteresis studies were performed to elucidate the magnetic behavior of the ruthenium decorated materials.
- Das, Manash R.,Das, Pankaj,Kalita, Gauravjyoti D.
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p. 13483 - 13496
(2021/10/12)
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- Selective primary aniline synthesis through supported Pd-catalyzed acceptorless dehydrogenative aromatization by utilizing hydrazine
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By utilizing hydrazine (N2H4) as the nitrogen source in the presence of a hydroxyapatite-supported Pd nanoparticle catalyst (Pd/HAP), various primary anilines can be selectively synthesized from cyclohexanonesviaacceptorless dehydrogenative aromatization. The strong nucleophilicity of N2H4and the stability of the hydrazone intermediates can effectively suppress the formation of the undesired secondary aniline byproducts.
- Lin, Wei-Chen,Yamaguchi, Kazuya,Yatabe, Takafumi
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supporting information
p. 6530 - 6533
(2021/07/07)
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- Regioselective Radical Arene Amination for the Concise Synthesis ofortho-Phenylenediamines
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The formation of arene C-N bonds directly from C-H bonds is of great importance and there has been rapid recent development of methods for achieving this through radical mechanisms, often involving reactiveN-centered radicals. A major challenge associated with these advances is that of regiocontrol, with mixtures of regioisomeric products obtained in most protocols, limiting broader utility. We have designed a system that utilizes attractive noncovalent interactions between an anionic substrate and an incoming radical cation in order to guide the latter to the areneorthoposition. The anionic substrate takes the form of a sulfamate-protected aniline and telescoped cleavage of the sulfamate group after amination leads directly toortho-phenylenediamines, key building blocks for a range of medicinally relevant diazoles. Our method can deliver both free amines and monoalkyl amines allowing access to unsymmetrical, selectively monoalkylated benzimidazoles and benzotriazoles. As well as providing concise access to valuableortho-phenylenediamines, this work demonstrates the potential for utilizing noncovalent interactions to control positional selectivity in radical reactions.
- Gillespie, James E.,Morrill, Charlotte,Phipps, Robert J.
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p. 9355 - 9360
(2021/07/19)
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- A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride
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The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.
- Kalola, Anirudhdha G.,Prasad, Pratibha,Mokariya, Jaydeep A.,Patel, Manish P.
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supporting information
p. 3565 - 3589
(2021/10/12)
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- Aluminum Metal-Organic Framework-Ligated Single-Site Nickel(II)-Hydride for Heterogeneous Chemoselective Catalysis
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The development of chemoselective and heterogeneous earth-abundant metal catalysts is essential for environmentally friendly chemical synthesis. We report a highly efficient, chemoselective, and reusable single-site nickel(II) hydride catalyst based on robust and porous aluminum metal-organic frameworks (MOFs) (DUT-5) for hydrogenation of nitro and nitrile compounds to the corresponding amines and hydrogenolysis of aryl ethers under mild conditions. The nickel-hydride catalyst was prepared by the metalation of aluminum hydroxide secondary building units (SBUs) of DUT-5 having the formula of Al(μ2-OH)(bpdc) (bpdc = 4,4′-biphenyldicarboxylate) with NiBr2 followed by a reaction with NaEt3BH. DUT-5-NiH has a broad substrate scope with excellent functional group tolerance in the hydrogenation of aromatic and aliphatic nitro and nitrile compounds under 1 bar H2 and could be recycled and reused at least 10 times. By changing the reaction conditions of the hydrogenation of nitriles, symmetric or unsymmetric secondary amines were also afforded selectively. The experimental and computational studies suggested reversible nitrile coordination to nickel followed by 1,2-insertion of coordinated nitrile into the nickel-hydride bond occurring in the turnover-limiting step. In addition, DUT-5-NiH is also an active catalyst for chemoselective hydrogenolysis of carbon-oxygen bonds in aryl ethers to afford hydrocarbons under atmospheric hydrogen in the absence of any base, which is important for the generation of fuels from biomass. This work highlights the potential of MOF-based single-site earth-abundant metal catalysts for practical and eco-friendly production of chemical feedstocks and biofuels.
- Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Dwivedi, Ashutosh,Manna, Kuntal
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p. 3943 - 3957
(2021/04/12)
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- Highly efficient N-doped carbon supported FeSx-Fe2O3 catalyst for hydrogenation of nitroarenes via pyrolysis of sulfurized N,Fe-containing MOFs
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Integrating MOFs as precursor, especially for employing N-containing organic linkers, with sulfides is an effective method to prepare the highly efficient N-doped carbon supported metal-based catalysts for hydrogenation of nitroarenes. In this work, a N,Fe-containing metal organic frameworks (MOFs; termed as MIL88-HMTA) with spindle-like structure was prepared via self-assembly method, in which hexamethylenetetramine (HMTA) linker was introduced as N source. Subsequently, N-doped carbon supported FeSx-Fe2O3 catalyst (named FeSx-Fe2O3@CN) was fabricated upon the pyrolysis of sulfurized MIL88-HMTA. Catalytic experiments reveal that the FeSx-Fe2O3@CN delivered excellent performance for hydrogenation of nitroarenes in comparison with those of catalyst without sulfidation process (Fe2O3@CN) and conventional MIL88 derived catalyst (Fe2O3@C). The XRD, TEM, SEM/EDX, Raman, UV, and XPS analyses have revealed that the developed FeSx-Fe2O3@CN catalyst exhibited outstanding catalytic efficiency was ascribed to synergistic effect between FeSx and Fe2O3 species, abundant structural defects, more Fe-Nx species, and strengthened decomposition ability of hydrazine hydrate (N2H4?H2O). Furthermore, the effect of sulfidation ratio (the mass ratio between thioacetamide and MIL88-HMTA) towards preparation of the developed FeSx-Fe2O3@CN on the catalytic activity of hydrogenation reaction was also systematically performed. Notably, the optimized catalyst (denoted as FeSx-Fe2O3@CN-8) exhibited unexpected performance and recyclability for hydrogenation of nitroarenes under mild condition. The pyrolysis of sulfurized N-containing MOFs may present a facile approach for fabricating MOFs-derived N-doped carbon supported catalysts, which provides a potential application in heterogeneous catalytic reactions.
- Li, Xuewei,She, Wei,Wang, Jing,Li, Weizuo,Li, Guangming
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- A novel water-dispersible and magnetically recyclable nickel nanoparticles for the one-pot reduction-Schiff base condensation of nitroarenes in pure water
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In this work, a heterogeneous nanocatalyst called Ni-Fe3O4@Pectin~PPA ~ Piconal was first synthesized, which was investigated as a bifunctional catalyst containing nickel functional groups. On the other hand, this Ni-Fe3O4@Pectin~PPA ~ Piconal catalyst in aqueous solvents shows a very effective performance at ambient temperature for the nitroarene reduction reaction with sodium borohydride, for which NaBH4 is considered as a reducing agent. This is a novelty magnetic catalyst that was approved by various methods, including Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), Dynamic light scattering (DLS), Transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), Inductively coupled plasma (ICP), Energy-dispersive X-ray spectroscopy (EDX), and Field emission scanning electron microscopy (FESEM) analyses. From the satisfactory results obtained from the reduction of nitrogen, this catalytic system is used for a one-pot protocol containing a reduction-Schiff base concentration of diverse nitroarenes. It was corroborated with the heterogeneous catalytic experiments on the one-pot tandem synthesis of imines from nitroarenes and aldehydes. Finally, the novel Ni-Fe3O4@Pectin~PPA ~ Piconal catalyst could function as a more economically desirable and environmentally amicable in the catalysis field. The favorable products are acquired in good to high performance in the attendance of Ni-Fe3O4@Pectin~PPA ~ Piconal as a bifunctional catalyst. This catalyst can be recycled up to six steps without losing a sharp drop.
- Ghamari Kargar, Pouya,Ravanjamjah, Asiye,Bagherzade, Ghodsieh
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p. 1916 - 1933
(2021/07/10)
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- Highly efficient hydrogenation reduction of aromatic nitro compounds using MOF derivative Co-N/C catalyst
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The direct hydrogenation reduction of aromatic nitro compounds to aromatic amines with non-noble metals is an attractive area. Herein, the pyrolysis of Co(2-methylimidazole)2 metal-organic framework successfully produces a magnetic Co-N/C nanocomposite, which exhibits a porous structure with a high specific area and uniform Co nanoparticle distribution in nitrogen-doped graphite. In addition, the Co-N/C catalysts possess high cobalt content (23%) with highly active β-Co as the main existing form and high nitrogen content (3%). These interesting characteristics endow the Co-N/C nanocomposite with excellent catalytic activity for the hydrogenation reduction of nitro compounds under mild conditions. In addition, the obtained Co-N/C nanocomposites possess a broad substrate scope and good cycle stability for the reduction of halogen-substituted or carbonyl substituted phenyl nitrates. This journal is
- Dai, Yuyu,Li, Xiaoqing,Wang, Likai,Xu, Xiangsheng
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p. 22908 - 22914
(2021/12/24)
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- Photocatalytic reduction of nitroaromatics into anilines using CeO2-TiO2 nanocomposite
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The reduction of nitro compounds into amines is an important approach for synthetic and pharmaceutical chemistry. The reduced compounds are used as synthetic intermediates in the synthesis of therapeutic molecules. In the present work, we have fabricated cerium dioxide decorated TiO2 nanoparticles using a sol-gel-hydrothermal method. The synthesized nanocomposite was effectively reduced various nitro-compounds, specifically aromatic nitro compounds, into amines in visible light. All the nitro compounds screened in the photoreduction reaction showed >90% conversion with >96% selectivity. Chromatographic techniques confirmed the products obtained. The nanocomposite photocatalyst has excellent stability under the experimental condition and exhibited up to five cycles with no loss of metal content. The nanomaterials were characterized using various spectroscopic techniques.
- Chen, Changdong,Lu, Caiyun,Sun, Chengxin,Wang, Fangfang,Yin, Zhengfeng
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- Method for preparing P-phenylenediamine
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The invention discloses a method for preparing high-purity p-phenylenediamine by reacting nitrobenzene with ammonia under the action of a catalyst to obtain 4-nitrosoaniline and 4-nitroaniline and then hydrogenating. Nitrobenzene and ammonia react under the action of a catalyst to generate 4-nitrosoaniline and 4-nitroaniline, the reaction selectivity is high, an ortho-position or meta-position product is not generated, and the yield is high. High-selectivity p-phenylenediamine can be obtained through catalytic hydrogenation of 4-nitrosoaniline and 4-nitroaniline, and the purity is high, so that the method is suitable for industrial production.
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Paragraph 0044-0068
(2021/01/24)
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- Method for synthesizing heteroatom- substituted aromatic compound from styrene compound
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The invention discloses a method for synthesizing a heteroatom-substituted aromatic compound from a styrene compound, which comprises the following steps of: mixing a styrene compound with a general formula (I) and a heteroatom-containing compound with a general formula (II), and reacting in the presence of an acid additive and an organic solvent to obtain a heteroatom-substituted compound with ageneral formula (III). According to the synthesis method disclosed by the invention, a large amount of styrene compounds are used as raw materials and react to generate aromatic amine or phenol compounds under the action of no metal catalysis; and compared with the traditional aromatic amine and phenol synthesis method, the method has the advantages of high yield, simple conditions, low waste discharge amount, no metal participation, simple reaction equipment, easiness in industrial production and the like.
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Paragraph 0161-0163; 0165
(2021/02/06)
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- Synthesis and characterization of chitosan pyridyl imine palladium (CPIP) complex as green catalyst for organic transformations
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In this work, the modification of chitosan using 2-acetyl pyridine has been used to prepare an intermediate, chitosan pyridyl imine (CPI), in first step and then in second step it is further reacted with Pd(OAc)2 to develop chitosan pyridyl imine palladium (CPIP) complex catalyst in a very simplistic way. The formed CPIP has been extensively characterized with respect to raw chitosan utilizing methods including FT-IR, pyrolysis GC–MS, XRD, XPS, FE-SEM, EDS, TGA-DTG and DSC. TG-DSC study suggested that the catalyst is thermally stable up to 300?°C. This catalyst shows an excellent activity in the reduction of toxic pollutant nitrobenzene to less toxic aniline. CPIP complex has also been found to give magnificent results in Suzuki–Miyaura and Heck cross-coupling reactions, and therefore, using this green catalyst, the toxic phosphine ligand can be excluded from cross-coupling reactions. This study furnishes an economic and eco-friendly catalyst for organic transformation in sustainable chemistry.
- Chundawat, Narendra Singh,Pathan, Sultan,Singh, Girdhar Pal,Deuri, Arup Saha,Zarrintaj, Payam,Chauhan, Narendra Pal Singh
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p. 2835 - 2850
(2021/02/11)
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- Reductive Formylation of Nitroarenes using HCOOH over Bimetallic C?N Framework Derived from the Integration of MOF and COF
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CoZn embedded C?N framework is prepared by the carbonization of CoZn containing MOF integrated with COF porous architecture in Ar atmosphere. The graphitic nature of porous carbon is confirmed from Raman analysis. The porosity and nanostructure information are retrieved from N2-sorption and transmission electron microscopic analysis, respectively. The incorporation of different metals and their oxidation states and types of nitrogen present in the C?N framework are confirmed from X-ray photoelectron spectroscopy. The basicity of the materials is determined from a CO2-temperature programmed desorption. ZnCo embedded C?N framework exhibits excellent activity in the selective reductive formylation using HCOOH. For comparison, more than 15 materials are prepared, and their activities are compared. Several control experiments are performed to establish a structure-activity relation. The recycling experiment, hot-filtration test, and poisoning experiment demonstrate the metal embedded porous C?N framework‘s recyclability and stability. A reaction mechanism for the reductive N-formylation of nitroaromatics is presented based on structure-activity relationship, control reactions, and physicochemical characterizations. The development of interesting MOF-COF-derived metal nanoclusters embedded C?N framework for selective reductive formylation of nitroaromatics using formic acid will be highly attractive to catalysis researchers and industrialists.
- Kumar Kar, Ashish,Srivastava, Rajendra
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p. 3174 - 3183
(2021/05/27)
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- Selective Carbon-Carbon Bond Amination with Redox-Active Aminating Reagents: A Direct Approach to Anilines?
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Amines are among the most fundamental motifs in chemical synthesis, and the introduction of amine building blocks via selective C—C bond cleavage allows the construction of nitrogen compounds from simple hydrocarbons through direct skeleton modification. Herein, we report a novel method for the preparation of anilines from alkylarenes via Schmidt-type rearrangement using redox-active amination reagents, which are easily prepared from hydroxylamine. Primary amines and secondary amines were prepared from corresponding alkylarenes or benzyl alcohols under mild conditions. Good compatibility and valuable applications of the transformation were also displayed.
- Qiu, Xu,Wang, Yachong,Su, Lingyu,Jin, Rui,Song, Song,Qin, Qixue,Li, Junhua,Zong, Baoning,Jiao, Ning
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supporting information
p. 3011 - 3016
(2021/09/13)
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- Preparation method of a plurality of (hetero) aromatic polyamines
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The invention relates to the field of organic functional new material chemicals, and discloses a novel process technology for preparing a plurality of (hetero) aromatic polyamines through corresponding (hetero) aromatic polyfunctional hydroxamic acids (hydroxamic acid) before (re-arrangement). These (hetero) aromatic polyamines are well-known dyes and pigment and pharmaceutical pesticide-related fields of very wide range of critical fine chemical materials.
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Paragraph 0044-0046
(2021/09/15)
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- Method for preparing P-phenylenediamine by adopting microreactor
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The invention discloses a method for preparing p-phenylenediamine by using a microreactor, which comprises the following steps: uniformly mixing a copper catalyst, a ligand, p-dichlorobenzene and ammonia in a batching kettle to form a mixed solution, and pumping the mixed solution into the microreactor to react to obtain p-phenylenediamine. According to the method, the catalyst ligand is added into the microreactor, so that the activity of the catalyst is improved, the reaction conditions are milder, the reaction efficiency is high, and the method is suitable for industrial production.
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Paragraph 0023-0034
(2021/01/04)
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- Preparation method of phenylenediamine (by machine translation)
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The preparation method comprises the following steps: in the presence of an organic solvent and a catalyst, taking dihalobenzene as a raw material, ammonia water as an ammonia solution, heating ammonolysis reaction under a low pressure of no more than 0.2 mpa to prepare phenylenediamine, wherein the complex metal ion is selected from Pd. 2 + Ni-Zn-Ni alloy2 + Ni, Co2 + Fe-Fe-B2 + Or Cu2 + At least one of the. In addition, the reaction process avoids the use of a mixed acid compound harmful to the environment, is green and environment-friendly, can be recycled, reduces the production cost and is beneficial to large-scale preparation. (by machine translation)
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Paragraph 0061-0062; 0069-0070
(2020/11/23)
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- Enhanced reduction of nitrobenzene derivatives: Effective strategy executed by Fe3O4/PVA-10%Ag as a versatile hybrid nanocatalyst
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Herein, we present an organic–inorganic hybrid nanocomposite constructed of polyvinyl alcohol (PVA), iron oxide (Fe3O4), and 10% of silver nanoparticles (Ag NPs). First, a convenient in situ method is introduced for the preparation of this efficient catalytic system (Fe3O4/PVA-10%Ag). Further, we study the high catalytic performance for the reduction of nitrobenzene (NB) derivatives as a hazardous species of chemicals and the significant biological activity (antibacterial effects) of the nanocomposite. However, high reaction yields (99%) have been obtained in short reaction times (~15 min). A plausible mechanism is suggested, and all the required characterizations of the presented nanocatalyst are investigated in this study.
- Rahimi, Jamal,Taheri-Ledari, Reza,Niksefat, Maryam,Maleki, Ali
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- Synthesis and characterization of a novel TEMPO?FeNi3/DFNS-laccase magnetic nanocomposite for the reduction of nitro compounds
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Water is an essential substance for life on earth and for all living things. Plants and animals need almost pure water to live; if it is contaminated with harmful chemicals and micro organisms, it will be impossible for them to survive. This study has tried to investigate the performance of catalyst to reduce nitro-aromatic combinations in the attendance of NaBH4 solution duo to the hydrogen source. TEMPO?FeNi3/DFNS-laccase MNPs was prepared, and its features were reviewed using SEM, TEM, XRD, TGA, VSM, AFM, and FTIR. Then, its strength as a nanocatalyst for removal of nitro-aromatic combinations was tested in contact time, initial concentration, the effects of pH and nanocatalyst amount was study. The results of this research proved that TEMPO?FeNi3/DFNS-laccase MNPs has a good return in removal of nitro-aromatic combinations, as its easy synthesis and reliable recovery.
- Mehrzad, Jamshid,Motavalizadehkakhky, Alireza,Saberi, Shima,Zhiani, Rahele
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p. 27297 - 27304
(2020/09/01)
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- Convenient conversion of hazardous nitrobenzene derivatives to aniline analogues by Ag nanoparticles, stabilized on a naturally magnetic pumice/chitosan substrate
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Herein, silver nanoparticles (Ag NPs), as an effective catalyst for the reduction process of nitrobenzene derivatives to non-hazardous and useful aniline derivatives, are conveniently synthesized on an inherently magnetic substrate. For this purpose, an efficient combination of volcanic pumice (VP), which is an extremely porous igneous rock, and a chitosan (CTS) polymeric network is prepared and suitably used for the stabilization of the Ag NPs. High magnetic properties of the fabricated Ag@VP/CTS composite, which have been confirmed via vibrating-sample magnetometer (VSM) analysis, are the first and foremost advantage of the introduced catalytic system since it gives us the opportunity to easily separate the particles and perform purification processes. Briefly, higher yields were obtained in the reduction reactions of nitrobenzenes (NBs) under very mild conditions in a short reaction time. Also, along with the natural biocompatible ingredients (VP and CTS) in the structure, excellent recyclability has been observed for the fabricated Ag@VP/CTS catalytic system, which convinces us to do scaling-up and suggests the presented system can be used for industrial applications. This journal is
- Taheri-Ledari, Reza,Mirmohammadi, Seyedeh Shadi,Valadi, Kobra,Maleki, Ali,Shalan, Ahmed Esmail
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p. 43670 - 43681
(2020/12/25)
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- Ultrasound-assisted diversion of nitrobenzene derivatives to their aniline equivalents through a heterogeneous magnetic Ag/Fe3O4-IT nanocomposite catalyst
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A heterogeneous magnetic catalytic system is fabricated and suitably applied for the fast and direct conversion of nitrobenzene (NB) derivatives to their aniline forms. For this purpose, different conditions and methods have been checked with numerous catalytic amounts of the nanocatalyst composite, which was constructed of iron oxide and silver nanoparticles and possessed an isothiazolone organic structure. Herein, the mechanistic aspect of the catalytic functioning of this highly efficient nanocatalyst is highlighted and discussed. Firstly, a convenient preparation route assisted by ultrasonication for this metal and metal oxide nanocomposite is presented. Further, a fast and direct reduction strategy for NBs is investigated using ultrasound irradiation (50 kHz, 200 W L-1). As two great advantages of this catalyst, high magnetic property and excellent reusability are also mentioned. This report well reveals that a really convenient conversion of NBs to anilines can be achieved with a high yield during the rapid reaction time in presence of mild reaction conditions. This journal is
- Taheri-Ledari, Reza,Rahimi, Jamal,Maleki, Ali,Shalan, Ahmed Esmail
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p. 19827 - 19835
(2020/12/04)
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- Simple reversible fixation of a magnetic catalyst in a continuous flow system: Ultrafast reduction of nitroarenes and subsequent reductive amination using ammonia borane
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Continuous reductive amination of aldehydes with nitroarenes over a Pd-Pt-Fe3O4 catalyst was performed. We used NH3BH3 as not only a hydrogen source for nitro reduction, but also a reductant for imine reduction. Secondary aromatic amines were obtained in the continuous flow reaction in good to excellent yields.
- Byun, Sangmoon,Cho, Ahra,Kang, Dong Yun,Kim, B. Moon,Kim, Ha Joon,Kim, Hong Won,Kim, Seong Min,Lei, Cao,Park, Jin Kyoon
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p. 944 - 949
(2020/03/11)
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- Tin(ii) chloride dihydrate/choline chloride deep eutectic solvent: Redox properties in the fast synthesis of: N -arylacetamides and indolo(pyrrolo)[1,2- a] quinoxalines
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In this contribution a physicochemical, IR and Raman characterization for the tin(ii) chloride dihydrate/choline chloride eutectic mixture is reported. The redox properties of this solvent were also studied by cyclic voltammetry finding that it can be successfully used as an electrochemical solvent for electrosynthesis and electroanalytical processes and does not require negative potentials as verified by the reduction of nitrobenzene. The potential use of this eutectic mixture as a redox solvent was further explored in obtaining aromatic amines and N-arylacetamides starting from a wide variety of nitroaromatic compounds. In addition, a fast synthetic strategy for the construction of a series of indolo(pyrrolo)[1,2-a]quinoxalines was developed by reacting 1-(2-nitrophenyl)-1H-indole(pyrrole) with aldehydes. This simple protocol offers a straightforward method for the construction of the target quinoxalines in short reaction times and high yields where the key step involves a tandem one-pot reductive cyclization-oxidation.
- Bejarano, Oscar Rodríguez,Ochoa-Puentes, Cristian,Pe?a-Solórzano, Diana,Trujillo, Sergio Alfonso
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p. 40552 - 40561
(2020/11/18)
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- Enhanced catalytic activity of natural hematite-supported ppm levels of Pd in nitroarenes reduction
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In this work, Pd NPs supported on amine-modified natural hematite have been prepared and characterized. Using this simple catalyst, nitroaromatic compounds as a major cause of industrial pollution were reduced to corresponding amines with ppm levels of Pd in the presence of designer surfactant TPGS-750-M and NaBH4 at room temperature in aqueous media. Synergistic effect between hematite and Pd is responsible for the observed enhanced catalytic activity. This catalyst was recycled for at least four times with a small decrease in the activity.
- Gholinejad, Mohammad,Shojafar, Mohammad,Sansano, José M.
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p. 2033 - 2043
(2020/04/07)
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- Palladium supported on metal–organic framework as a catalyst for the hydrogenation of nitroarenes under mild conditions
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Sustainable development demands an environmentally friendly and efficient method for the hydrogenation of organic molecules, including the hydrogenation of functionalized nitroarenes. In this study, a highly active and selective metal–organic framework-supported palladium catalyst was prepared for the catalytic hydrogenation of nitroarenes. High selectivity (>99%) and excellent yield (98%) of aniline were realized after 2 hours in ethanol under hydrogen (1 atm) at room temperature. The reductions were successfully carried out in the presence of a wide range of other reducible functional groups. More importantly, the catalyst was very stable without the loss of its catalytic activity after five cycles.
- Bao, Lingxiang,Fei, Teng,Li, Jiazhe,Pang, Siping,Sun, Chenghui,Yan, Zhiyuan,Yu, Zongbao
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- Synthesis and characterization of go-chit-ni nanocomposite as a recoverable nanocatalyst for reducing nitroarenes in water
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In the present study, nickel nanoparticles (Ni-NPs) immobilized on graphene oxide-chitosan (GO-Chit-Ni) have been synthesized and characterized as a catalyst for reduction of nitroarenes in water. For this purpose, GO has been functionalized with chitosan (GO-Chit). Then, Ni-NPs were immobilized on the surface of GO-Chit using a simple method. The GO-Chi-Ni nanocomposites were characterized using Fourier Transforms Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), X-Ray Diffraction Measurements (XRD), and Atomic Adsorption Spectrometry (AAS). The GO-Chi-Ni nanoparticles demonstrated appropriate catalytic activity in reducing nitroarenes to aryl amines in the existence of sodium borohydride (NaBH4) aqueous solution as a hydrogen source at 80oC. This catalytic system applies environmentally benign water as a solvent that is cheap, easily accessible, non-toxic, non-volatile, non-flammable and thermally stable. This type of catalyst can be applied several times with no considerable change in its performance.
- Azadi, Roya,Sarvestani, Mosayeb
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p. 523 - 531
(2020/07/17)
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- CO-free, aqueous mediated, instant and selective reduction of nitrobenzeneviarobustly stable chalcogen stabilised iron carbonyl clusters (Fe3E2(CO)9, E = S, Se, Te)
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Highly stable and thermally robust iron chalcogenide carbonyl clusters Fe3E2(CO)9(E = S, Se or Te) have been explored for the reduction of nitrobenzene. A 15 min thermal heating of an aqueous solution of nitrobenzene and hydrazine hydrate in the catalytic presence of Fe3E2(CO)9(E = S, Se or Te) clusters yield average to excellent aniline transformations. Among the S, Se and Te based iron chalcogenised carbonyl clusters, the diselenide cluster was found to be most efficient and produce almost 90% yield of the desired amino product, the disulfide cluster was also found to be significantly active, produce the 85% yield of amino product, while the ditelluride cluster was not found to be active and produced only 49% yield of the desired product. The catalyst can be reused up to three catalytic cycles and it needs to be dried in an oven for one hour prior to reuse for the best results. The developed method is inexpensive, environmentally benign, does not require any precious metal or a high pressure of toxic CO gas and exclusively brings the selective reduction of the nitro group under feasible and inert free conditions.
- Joshi, Raj Kumar,Kumari, Sangeeta,Sharma, Charu,Soni, Aditi,Srivastava, Avinash Kumar
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p. 32516 - 32521
(2020/09/17)
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- Selective Liquid Phase Hydrogenation of Aromatic Nitro Compounds in the Presence of Fe–Cu Nanoparticles
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Abstract: Fe–Cu bimetallic oxide nanoparticles supported on silica gel that catalyze the hydrogenation of nitrobenzene to aniline and of dinitrobenzenes to phenylenediamines under relatively mild reaction conditions (200°C, pH2 1.3 MPa, 4 h, and 700 rpm) are synthesized. The catalytic properties of supported bimetallic Fe–Cu catalysts depend on the synthesis procedure, sample composition, and conditions of thermal treatment. There is a synergistic effect of interaction between Cu and Fe in the hydrogenation of nitrobenzene, 1,3-dinitrobenzene, and 1,4-dinitrobenzene in the presence of a bimetallic Fe–Cu catalyst obtained via coprecipitation.
- Shesterkina,Strekalova,Kustov
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p. 1180 - 1183
(2020/06/08)
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- Zn(0)-Catalysed mild and selective hydrogenation of nitroarenes
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The hydrogenation of nitroarenes is one of the most important strategies for the preparation of anilines. However, it is still a great challenge to develop mild and efficient synthetic routes toward aniline synthesis, particularly those employing both non-precious metal catalysts and low-pressure H2. Herein, we report a highly efficient protocol for the selective hydrogenation of nitroarenes in neutral H2O using H2 (1 atm) over a heterogeneous Zn(0) catalyst under mild conditions. The nitro groups of an array of nitroarenes can be converted into -NH2 with up to 99percent conversions and a selectivity of >99percent, even when functionalized with easily reducible substituents, or in the presence of aromatic ketones or styrene. This study might open an avenue for the selective hydrogenation of nitroarenes over a zinc catalyst using 1 atm H2.
- Du, Muyao,Hu, Pan,Jv, Xinchun,Sun, Shuting,Wang, Bo,Zhang, Qun,Zhao, Ruixiang
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supporting information
p. 4640 - 4644
(2020/08/10)
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