99-05-8Relevant academic research and scientific papers
Copper nanoparticles (CuNPs) catalyzed chemoselective reduction of nitroarenes in aqueous medium
Chand, Dillip Kumar,Rai, Randhir
, (2021/08/20)
Abstract: A procedure for practical synthesis of CuNPs from CuSO4·5H2O is established, under appropriate reaction conditions, using rice (Oryza sativa) as an economic source of reducing as well as a stabilizing agent. Optical and microscopic techniques are employed for the characterization of the synthesized CuNPs and the sizes of the particles were found to be in the range of 8 ± 2 nm. The nanoparticles are used as a catalyst for chemoselective reduction of aromatic nitro compounds to corresponding amines under ambient conditions and water as a reaction medium. Graphic abstract: CuNPs are synthesized using hydrolysed rice and used as catalyst for chemoselective reduction of nitroarenes to their corresponding amines in water. [Figure not available: see fulltext.]
Selective reduction of nitro-compounds to primary amines by tetrapyridinoporphyrazinato zinc (II) supported on DFNS
Hosseiny, Malihesadat,Khosroyar, Susan,Kiani, Zahra,Motavalizadehkakhky, Alireza,Zhiani, Rahele
, (2021/06/14)
Here, we created and synthesized a heterogeneous catalyst from porphyrazinatozinc (tmtppa-Zn) supported on DFNS (tmtppa-Zn/DFNS). This is a simple method for hydrogenation of nitro-compounds and their conversion to primary amines without producing toxic by-products. These reactions take place under mild reaction situations. The catalyst system was comfortably retrieved and reutilized in at least ten runs without the reduction of catalytic activity.
Cobalt oxide NPs immobilized on environmentally benign biological macromolecule-derived N-doped mesoporous carbon as an efficient catalyst for hydrogenation of nitroarenes
Elhampour, Ali,Nanadegani, Zahra Soleimani,Nemati, Firouzeh,Rangraz, Yalda
, (2020/09/15)
Highly nitrogen-doped mesoporous carbon (N-mC) material incorporated cobalt oxide nanoparticles was synthesized through simple pyrolysis of environmentally friendly chitosan-polyaniline-Co(OAc)2 precursor in one-step. The as-prepared catalyst named CoO&at;N-mC with 14.65 ?wtpercent nitrogen content was characterized by different analysis techniques. The heterogeneous catalyst exhibits outstanding catalytic activity for the reduction of a variety of nitroaromatic compounds in the presence of NaBH4 as a reducing agent in water as a green solvent at 75 ?°C. Utilization of natural biological macromolecules such as chitosan as green and cheap starting material with harmless aniline and earth-abundant cobalt salt, facile synthesis, excellent product yield, short reaction time, high chemoselectivity, sustainable and mild reaction condition, and reusability of catalyst for at least five cycles without any significant decline in the catalytic efficiency are some prominent merits of this new nanocatalyst.
Palladium Supported on Carbon Nanoglobules as a Promising Catalyst for Selective Hydrogenation of Nitroarenes
Mironenko,Belskaya,Stepanova,Gulyaeva,Trenikhin,Likholobov
, p. 888 - 900 (2019/11/11)
The catalysts 1?wt% palladium supported on carbon nanoglobules (CNGs) were shown to be highly active in the liquid-phase hydrogenation of various nitroarenes and provided nearly 100% selectivity to aromatic amines at complete conversion under mild conditions (323?K, 0.5?MPa, 1?h). The catalytic activity (in terms of turnover frequency and substrate conversion) and selectivity depend on the kind of CNGs support, catalyst preparation method and the reaction conditions (solvent nature). The Pd/CNGs catalyst can be repeatedly used while maintaining the same catalytic performance. The excellent performances of Pd/CNGs catalysts can be due to the globular morphology of the supports as well as the absence of micropores and pronounced surface defects. Graphic Abstract: [Figure not available: see fulltext.]
Differences in the selective reduction mechanism of 4-nitroacetophenone catalysed by rutile- And anatase-supported ruthenium catalysts
Gu, Xianmo,Pei, Linjuan,Wang, Jie,Zhang, Jin,Zheng, Zhanfeng,Zhu, Pengqi
, p. 1518 - 1528 (2020/03/26)
Ru/TiO2 catalysts exhibit excellent catalytic performance for selective reduction of 4-nitroacetophenone to 4-aminoacetophenone at normal temperature and atmospheric hydrogen pressure. Moreover, 99.9% selectivity to 4-aminoacetophenone can be obtained over 2.7 wt% Ru/TiO2(anatase) catalyst even in a relatively wide temperature (55-115 °C) and time (1-12 h) range. Its excellent catalytic performance is derived from the activation of H2 on the Ru nanoparticles at atmospheric pressure and the strong interaction of nitro groups with the support surface. Additionally, Ru nanoparticles supported on different crystalline TiO2 phases (anatase and rutile) result in different reaction pathways for 4-nitroacetophenone. Since the Ti-Ti distance on the rutile surface is smaller than that on the anatase surface, the hydroxylamine species adsorbed on the Ti atoms of rutile are more susceptible to the coupling reaction. Therefore, Ru/TiO2(rutile) causes a series of intermediates to accumulate during the conversion process, while Ru/TiO2(anatase) allows the highly selective conversion of 4-nitroacetophenone to 4-aminophenone. In addition, Ru/TiO2(anatase) can achieve chemoselective reduction of nitroaromatics to the corresponding anilines in the presence of -CN, -CHO, and -COOH, especially nitroaromatics containing CC and CC, indicating the excellent applicability.
Acceptorless dehydrogenative oxidation of primary alcohols to carboxylic acids and reduction of nitroarenes via hydrogen borrowing catalyzed by a novel nanomagnetic silver catalyst
Yazdani, Elahe,Heydari, Akbar
supporting information, (2020/08/14)
A novel silver nano magnetic catalyst was devised for dehydrogenative oxidation of aromatic and aliphatic alcohols to the corresponding acid with water as the sole oxygen source and hydrogen gas as the only by-product. The designed catalytic system advantages from easy recovery of magnetic materials i.e. magnetic decantation, being economically viable and environmentally friendly. Furthermore, the catalytic reaction is able to reduce aryl nitro compounds in the absence of any reducing agent.
A polyamine dendritic polymer-copper complex: A reusable catalyst for the additive-free amination of aryl bromides, and iodides
Avudaiappan,Palmurukan,Unnikrishnan,Sreekumar
, p. 1477 - 1484 (2020/02/05)
A porphyrin-initiated amine-functionalized polyepichlorohydrin dendritic polymer (PPECH-Amine) was effectively synthesized, and its water-soluble copper complex (PPECH-Amine-Cu) was developed by treating it with copper acetate. PPECH-Amine and PPECH-Amine-Cu were characterised by different spectroscopic and microscopic techniques. PPECH-Amine-Cu was identified as a reusable catalyst for the amination of bromo- and iodo-benzene derivatives in aqueous media. Due to the presence of residual amino groups in the PPECH-Amine-Cu catalyst, the protocol does not need any additional base additive, as ammonia itself acts as a base and a coupling partner. Due to the good water-soluble nature of this catalyst, it can be easily separated and reused up to six reaction cycles without any loss in its activity.
Phase and shape dependent photoactivity of titania for nitroaromatics reduction under UV light irradiation
Kaur, Jaspreet,Pal, Bonamali
, p. 803 - 809 (2018/12/14)
This work describes importance of TiO2 nanostructures of different shapes (nanospheres and nanorods) and crystal phases (anatase and rutile) for the photoreduction of nitroaromatics into corresponding aminoaromatics under UV light irradiation. Anatase nanoparticles were most active of all the catalysts due to the superior stability of this phase and comparatively the rutile nanorods (L×W = 28-30 nm×3.5-3.8 nm) showed superior photoactivity (～3 times) as compared to rutile nanospheres of size 122 nm for the photoreduction due to electron transport along longitudinal length, larger surface area (69 m2g-1), quenched PL emission, increased lifetime of charge carriers (1.8 ns) of rutile nanorods as compare to rutile nanospheres having lower surface area (18 m2g-1) and charge carrier lifetime (1.1 ns). The overall rate of reduction/hour for m-NBA and m-NT photoreduction with all of these catalysts has been found to vary in the following order ANP > P25-TiO2 > RNR > ANR > RNP.
Synergistic Effects of ppm Levels of Palladium on Natural Clinochlore for Reduction of Nitroarenes
Gholinejad, Mohammad,Oftadeh, Erfan,Shojafar, Mohammad,Sansano, José M.,Lipshutz, Bruce H.
, p. 4240 - 4248 (2019/09/06)
Augmenting the modified naturally occurring clay clinochlore with ppm amounts of palladium leads to a new and very effective reagent for the reduction of numerous aromatic nitro species. When palladium nanoparticles are supported on pyridyltriazole-modified clinochlore, iron within clinochlore acts synergistically with palladium to catalyze the reduction of a wide variety of nitroarenes at room temperature in aqueous media. Based on E-factor calculations, the catalyst system is found to be in line with green chemistry standards and can be recycled up to five times.
Palladium complex containing diphosphine m-carborane ligand as well as preparation and application of palladium complex
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Paragraph 0063-0066, (2019/12/02)
The invention relates to a palladium complex containing a diphosphine m-carborane ligand as well as a preparation and an application of the palladium complex. The preparation method of the palladium complex comprises the following steps of 1) adding an n-BuLi solution into a m-carborane solution, and then reacting for 30-60 minutes at a room temperature; 2) adding diphenyl phosphorus chloride, andreacting for 3-6 h at the room temperature; and 3) adding PdCl2, reacting at the room temperature for 3-5 hours, and carrying out post-treatment to obtain the palladium complex. The palladium complexis used for catalyzing the reaction of halohydrocarbon with carbon dioxide to synthesize carboxylic acid. Compared with the prior art, the synthesis process is simple and green, and has the excellentselectivity and high yield; the palladium complex has the stable physicochemical properties and is used as the catalyst, the halogenated hydrocarbon is used as a substrate, the palladium complex andthe halogenated hydrocarbon are jointly dissolved in toluene, and the carbon dioxide is introduced at the normal pressure for reaction, so that the corresponding carboxylic acid can be synthesized athigh yield.
