2243-62-1Relevant articles and documents
Activated carbon supported bimetallic catalysts with combined catalytic effects for aromatic nitro compounds hydrogenation under mild conditions
Huang, Lei,Lv, Yang,Wu, Shengtao,Liu, Pingle,Xiong, Wei,Hao, Fang,Luo, He'an
, p. 76 - 85 (2019)
Non-noble nickel catalysts have been widely studied and tried in hydrogenation, however the problem of nickel particle sintering is more and more common in high-loaded nickel catalysts. A series of highly dispersed bimetallic Ni-M/AC (M = Cu, Co, Fe or Zn) catalysts were prepared by incipient wetness impregnation methods and applied in 1-nitronaphthalene hydrogenation to 1-naphthylamine under mild reaction conditions. The prepared catalysts were characterized by XRD, BET, H2-TPR, TEM, HRTEM, HAADF-STEM, XPS, ICP, FT-IR and H2 chemisorption. The results show that the introduction of the metal promoter inhibits the sintering of the nickel and enhances the reducibility of the catalysts, leading to higher ratio of effective Ni° on the surface of the support, especially for Ni-Zn/AC sample. Moreover, the results of XPS indicate that the electron donating effect of Cu promoter increases surface electronic density of Ni, as a result, the electron-rich Ni might be produced because of the interfacial electronic effect, which favors the desorption and further impedes the hydrogenation of N-naphthylhydroxylamine. Ni-Zn/AC-350 with smaller nickel particles, better dispersion and larger content of effective Ni° presents the best catalytic performance in 1-nitronaphthalene hydrogenation to 1-naphthylamine under mild reaction conditions, it gives 100% conversion of 1-nitronaphthalene and 96.82% selectivity to 1-naphthylamine under 0.6 MPa and 90℃ for 5 h. Additionally, superior performances are also obtained in hydrogenation reactions of nitrobenzene, chloronitrobenzene, 1,5-dinitronaphthalene and 1,8-dinitronaphthalene over Ni-Zn/AC catalysts. With good hydrogenation activity the catalyst shows, the application prospect in industrial production of aromatic amine from aromatic nitro compounds has been becoming more and more extension.
Carbon networks based on 1,5-naphthalene units. Synthesis of 1,5-naphthalene nanostructures with extended π-conjugation
Rodriguez, J. Gonzalo,Tejedor, J. Luis
, p. 7631 - 7640 (2002)
The synthesis and spectroscopic characterization of nanometer-sized conjugated molecules of 5-X-naphthylethynyl (X= NO2, NMe2) units with precise length and constitution have been carried out. A new extended π-conjugated 5-nitronaphthyl family was synthesized by palladium-catalyzed cross-coupling reaction between the protected 5-iodonaphthylethynyl 5a and 1-ethynyl-5-nitronaphthalene 9, or the resulting ethynyl compound 11 and the 1-iodo-5-nitronaphthalene 3. Catalytic oxidative dimerization of the terminal acetylene compounds permits the isolation of the corresponding 1,3-butadiyne derivatives 16-18, with the nitro groups at the ends of the conjugation, in excellent yields. A new family of conjugated 5-nitro-(naphthylethynyl)-[5-(N,N-dimethylamino)]-naphthalene (20-22), was also synthesized by palladium-catalyzed cross-coupling reaction between 5-iodo-N,N-dimethylnaphthalene-1-amine (19) with the appropriate terminal acetylene (9, 11, and 13 respectively). Compounds 20-22 show a fluorescence emission and also exhibit a charge-transfer absorption in the visible spectrum. X-ray structure of 20 confirms a centrosymmetric dimer association with an interplanar distance of 3.43 A, and the naphthalene rings adopt an anti conformation around the C≡C triple bond.
Synthesis of 1,5-naphthylethynyl nanostructure networks with extended π-conjugation. Effective heterocoupling catalyzed by palladium under a compatible CO2 atmosphere
Rodríguez, J. Gonzalo,Tejedor, J. Luis
, p. 2691 - 2693 (2003)
The synthesis of a new extended π-conjugated 5-N,N-dimethylaminonaphthyl family was undertaken by palladium-catalyzed cross-coupling reaction between a protected 5-iodonaphthylethynyl and 1-ethynyl-5-(N,N-dimethylamino)naphthalene. Under an argon atmosphere, only the homocoupling product 1,4-(N,N-dimethylamino)naphthyl-1,3-butadiyne was isolated, in excellent yield. However, under a compatible and pure carbon dioxide atmosphere, the cross-coupling product was obtained in excellent yield.
Synthesis, structure and catalytic activity of the supported Ni catalysts for highly efficient one-step hydrogenation of 1,5-dinitronaphthalene to 1,5-diaminodecahydronaphthalene
Lu,Wei,Zhou,Jiang,Sun,Xia
, p. 196 - 206 (2015)
A series of the supported nickel catalysts have been synthesized through impregnation, characterized by X-ray diffraction, N2 sorption measurement, temperature programmed H2 reduction and X-ray photoelectron spectroscopy. The morphology and particle size of catalysts are imaged by scanning electron microscope. The catalysts have efficiently catalyzed the one-step hydrogenation of 1,5-dinitronaphthalene to 1,5-diaminodecahydronaphthalene. The catalyst 10%Ni/SiO2-1a is the most active for the titled hydrogenation with 100 mol% conversion and 95.3% selectivity, applicable for the catalytic one-step hydrogenation of nitro-aromatic compounds. The reducibility of NiO species on different supports has been carefully studied. Some factors such as the type of carriers, the addition of modifiers, the silica source, the Ni loading, the H2 pressure and the reaction temperature and time play important roles in controlling the hydrogenation. In addition, the negative effect of the water amount has been observed. The recycling tests reveal the recyclability and stability of the supported Ni catalyst.
Half-Sandwich Ruthenium Complexes of Amide-Phosphine Based Ligands: H-Bonding Cavity Assisted Binding and Reduction of Nitro-substrates
Pachisia, Sanya,Kishan, Ram,Yadav, Samanta,Gupta, Rajeev
, p. 2009 - 2022 (2021/02/06)
We present synthesis and characterization of two half-sandwich Ru(II) complexes supported with amide-phosphine based ligands. These complexes presented a pyridine-2,6-dicarboxamide based pincer cavity, decorated with hydrogen bonds, that participated in the binding of nitro-substrates closer to the Ru(II) centers, which is further supported with binding and docking studies. These ruthenium complexes functioned as the noteworthy catalysts for the borohydride mediated reduction of assorted nitro-substrates. Mechanistic studies not only confirmed the intermediacy of [Ru-H] in the reduction but also asserted the involvement of several organic intermediates during the course of the catalysis. A similar Ru(II) complex that lacked pyridine-2,6-dicarboxamide based pincer cavity substantiated its unique role both in the substrate binding and the subsequent catalysis.
Efficient hydrogenation catalyst designing via preferential adsorption sites construction towards active copper
Dai, Xingchao,He, Dongcheng,Li, Teng,Shi, Feng,Wang, Hongli,Wang, Tao,Wang, Xinzhi
, p. 397 - 406 (2021/07/21)
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.
One-step catalytic amination of naphthalene to naphthylamine with exceptional yield
Hao, Fang,Wang, Xin,Huang, Linfang,Xiong, Wei,Liu, Pingle,Luo, Hean
supporting information, p. 2744 - 2749 (2020/06/17)
One-step amination of aromatic compounds to arylamines is a promising strategy with high atom economy and less environmental pollution. We propose for the first time a direct catalytic amination of naphthalene to naphthylamine and hydroxylamine using vanadium catalysts under mild conditions. Naphthylamine was obtained in 70% yield over the V2O5/HZSM-5 cayalyst in a one-step amination of naphthalene, which is higher than the yield obtained by state-of-the-art processes. The Br?nsted acid sites, and the V-O-V and VO bonds of monovanadate in the V2O5/HZSM-5 catalyst are the active sites for the amination reaction and are responsible for the naphthalene activation and formation of NH3+ that acts as the active amination reagent. A possible reaction mechanism was also proposed by investigating real-time IR and in situ DRIFTS. This proposed one-step amination of naphthalene is superior to traditional nonselective nitration and hydrogenation processes, and some findings offer new insights to produce arylamines from aromatic compounds.
A capping agent dissolution method for the synthesis of metal nanosponges and their catalytic activity towards nitroarene reduction under mild conditions
Ghosh, Sourav,Jagirdar, Balaji R.
, p. 17401 - 17411 (2019/01/03)
We report a general strategy for the synthesis of metal nanosponges (M = Ag, Au, Pt, Pd, and Cu) using a capping agent dissolution method where addition of water to the M@BNHx nanocomposite affords the metal nanosponges. The B-H bond of the BNHx polymer gets hydrolysed upon addition of water and produces hydrogen gas bubbles which act as dynamic templates leading to the formation of nanosponges. The rate of B-H bond hydrolysis has a direct impact on the final nanostructure of the materials. The metal nanosponges were characterized using powder XRD, electron microscopy, XPS, and BET surface area analyzer techniques. The porous structure of these nanosponges offers a large number of accessible surface sites for catalytic reactions. The catalytic activity of these metal nanosponges has been demonstrated for the reduction of 4-nitrophenol where palladium exhibits the highest catalytic activity (k = 0.314 min?1). The catalytic activity of palladium nanosponge was verified for the tandem dehydrogenation of ammonia borane and the hydrogenation of nitroarenes to arylamines in methanol at room temperature. The reduction of various substituted nitroarenes was proven to be functional group tolerant except for a few halogenated nitroarenes (X = Br and I) and >99% conversion was noted within 30-60 min with high turnover frequencies (TOF) at low catalyst loading (0.1 mol%). The catalyst could be easily separated out from the reaction mixture via centrifugation and was recyclable over several cycles, retaining its porous structure.
By the 1 - naphthylamine synthetic 1, 5 - diaminonaphthalene method two
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Paragraph 0028; 0031; 0033; 0036; 0037-0038; 0040; 0042, (2017/11/23)
The invention discloses a method for synthesizing 1,5-diaminonaphthalene with 1-naphthylamine. The method is characterized in that in a mixed solvent of glacial acetic acid and water, 1-naphthylamine and hydroxylammonium salts carry out one-step reaction in the presence of catalysts, namely metavanadate and/or vanadium oxide, to generate 1,5-diaminonaphthalene. The method is low in cost, simple in process, short in flow and mild in reaction conditions, is environment-friendly and meets the industrial production requirements.
METHOD FOR SPECIFIC CLEAVAGE OF C Alpha-C BOND AND SIDE CHAIN OF PROTEIN AND PEPTIDE, AND METHOD FOR DETERMINING AMINO ACID SEQUENCE
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, (2017/12/15)
The present invention provides a method for specifically cleaving a Cα-C bond of a peptide backbone and/or a side chain of a protein and a peptide, and a method for determining amino acid sequences of protein and peptide. A method for specifically cleaving a Cα-C bond of a peptide backbone and/or a side chain bond of a protein or a peptide, comprising irradiating a protein or a peptide with laser light in the presence of at least one hydroxynitrobenzoic acid selected from the group consisting of 3-hydroxy-2-nitrobenzoic acid, 4-hydroxy-3-nitrobenzoic acid, 5-hydroxy-2-nitrobenzoic acid, 3-hydroxy-5-nitrobenzoic acid, and 4-hydroxy-2-nitrobenzoic acid. A method for determining an amino acid sequence of a protein or a peptide, comprising irradiating a protein or a peptide with laser light in the presence of the above specific hydroxynitrobenzoic acid to specifically cleave a Cα-C bond of a peptide backbone and/or a side chain bond, and analyzing generated fragment ions by mass spectrometry.
