3862-73-5Relevant academic research and scientific papers
Pd-CATALYZED AMINATION OF FLUORINATED ARYL CHLORIDES
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Page/Page column 12; 13, (2021/10/15)
The presently claimed invention relates to a process for the preparation of di-, tri-, or tetra fluoroarylamine by reacting polyfluorinated aryl chlorides with ammonia in the presence of a base, a metal catalyst and a ligand. Di-, tri-, tetrafluoroarylamines are valuable intermediates and find application in several areas, mainly in epoxy polymers, colorants, dyes, polyurethanes, agrochemicals and pharmaceutical active agents.
Preparation method of 3, 4, 5-trifluorobromobenzene
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, (2020/12/14)
The invention relates to a preparation method of 3, 4, 5-trifluorobromobenzene, belongs to the technical field of chemical synthesis, and solves the problem that a byproduct 3, 4, 5-trichloronitrobenzene generated in a process of preparing 3, 4-dichloronitrobenzene by introducing chlorine into parachloronitrobenzene cannot be effectively utilized. The method comprises the step of preparing 3, 4, 5-trifluorobromobenzene by taking 3, 4, 5-trichloronitrobenzene as a raw material. According to the technical scheme provided by the invention, the utilization rate of raw materials and the efficiencyof the process can be improved, and high-value utilization of byproducts is realized.
Highly selective hydrogenation of halogenated nitroarenes over Ru/CN nanocomposites by: In situ pyrolysis
Yue, Shengnan,Wang, Xueguang,Li, Shaoting,Sheng, Yao,Zou, Xiujing,Lu, Xionggang,Zhang, Chunlei
, p. 11861 - 11869 (2020/07/28)
A highly chemoselective and recyclable ruthenium catalyst for the hydrogenation of halogenated nitroarenes has been prepared via the simple in situ calcination of a mixture of melamine, glucose and ruthenium trichloride. Superfine Ru particles (2.3 ± 0.3 nm) were obtained and highly dispersed in the nitrogen-doped carbon matrix. The Ru/CN catalyst smoothly transforms a variety of halogenated nitroarenes to the corresponding haloanilines with high intrinsic activity (e.g. TOF = 1333 h-1 for p-chloronitrobenzene) and selectivity of more than 99.6percent. Furthermore, through an analysis of the products in the reaction process, it was concluded that there are two parallel reaction pathways (a direct pathway and an indirect pathway) for the hydrogenation of aromatic nitro compounds over the Ru/CN catalyst, and the direct pathway was proved to be dominant in catalyzing the intermediates. This journal is
Method for producing 2,3,4-trifluoroaniline by adopting solvent-free catalytic hydrogenation
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Paragraph 0018-0033, (2019/01/06)
The invention provides a method for producing 2,3,4-trifluoroaniline by adopting solvent-free catalytic hydrogenation. According to the method, 2,3,4-trifluoronitrobenzene is taken as a raw material;and the 2,3,4-trifluoronitrobenzene is subjected to catalytic hydrogenation, without a solvent, in the presence of a catalyst and phosphates in a high-pressure reactor so as to prepare the 2,3,4-trifluoroaniline. Compared with existing hydrogenation with solvents, the solvent-free hydrogenation adopted by the method is greatly increased in reaction efficiency, so that the equipment utilization rate is obviously improved; at the same time, energy consumption and equipment cost due to solvent recovery are also effectively avoided, so that the method is a green and pollution-free environment-friendly technology which is capable of effectively avoiding production of a large amount of waste water and waste residues. The method for producing the 2,3,4-trifluoroaniline by adopting the solvent-free catalytic hydrogenation utilizes a noble metal catalyst Pt/C, and the catalyst is simple in preparation process and can be recycled in the reaction; moreover, the noble metal can be recycled, so that the production cost is further reduced. In addition, the utilized phosphates can be used as a dehydrogenation inhibitor, and are capable of increasing the reaction conversion rate.
Preparation of Well-Ordered Mesoporous-Silica-Supported Ruthenium Nanoparticles for Highly Selective Reduction of Functionalized Nitroarenes through Transfer Hydrogenation
Wei, Ning,Zou, Xiujing,Huang, Haigen,Wang, Xueguang,Ding, Weizhong,Lu, Xionggang
supporting information, p. 209 - 214 (2018/01/26)
MCM-41-type mesoporous silica (OMS-IL) was prepared by using an ionic liquid (1-hexadecyl-3-methylimidazolium bromide) as a template. The XRD and TEM results demonstrated that OMS-IL was more stable than the MCM-41 material. Ru nanoparticles were supported on OMS-IL (Ru/OMS-IL) by impregnating OMS-IL with a RuCl3 aqueous solution, and the resulting material was used for the selective reduction of nitroarenes. The effects of the components of the catalysts and the reaction conditions on the catalytic behavior of the prepared catalysts were investigated in detail. Ru/OMS-IL exhibited high catalytic activity and chemoselectivity for the reduction of various substituted nitroarenes to the corresponding aromatic amines in ethanol with hydrazine hydrate as a hydrogen donor under mild conditions. The Ru/OMS-IL catalysts were highly stable and could easily be recovered by simple filtration over at least six recycling reactions without any observable loss in catalytic performance.
N-doped graphitic carbon-improved Co-MoO3 catalysts on ordered mesoporous SBA-15 for chemoselective reduction of nitroarenes
Huang, Haigen,Liang, Xiangcheng,Wang, Xueguang,Sheng, Yao,Chen, Chenju,Zou, Xiujing,Lu, Xionggang
, p. 127 - 137 (2018/05/04)
Metallic Co-MoO3 catalysts supported on ordered mesoporous SBA-15 were first prepared through in situ reaction of SBA-15-supported Co-Mo oxides with 1,10-phenanthroline. The resulting Co-MoO3/NC@SBA-15 catalysts with N-doped carbon (NC) exhibited high catalytic activity and chemoselectivity for selective reduction of various functionalized nitroarenes to the corresponding arylamines in ethanol with hydrazine hydrate at near room temperature (30 °C). For reduction of all tested substrates (28 examples), the catalyst could afford a conversion of >99% and arylamine selectivity of >99%. The excellent catalytic performance of the Co-MoO3/NC@SBA-15 was attributed to the Co-Nχ(C)-Mo active sites generated through the interaction between the surface Co-Nχ(C) and MoO3 species, promoting the dissociation of hydrazine molecule into the active H* species for the reduction of nitro groups. After the seventh cycle for reduction of 4-methoxylnitrobenzene, the 2%Co-MoO3/NC@SBA-15 showed little change in catalytic performance, textural properties, size and dispersion of metal species and valence states of elements, indicating high stability and recyclability.
High Performance and Active Sites of a Ceria-Supported Palladium Catalyst for Solvent-Free Chemoselective Hydrogenation of Nitroarenes
Shi, Xiuxiu,Wang, Xueguang,Shang, Xingfu,Zou, Xiujing,Ding, Weizhong,Lu, Xionggang
, p. 3743 - 3751 (2017/10/16)
Cerium oxide-supported palladium catalysts (Pd/CeO2) prepared by a simple impregnation method exhibit exciting catalytic activity and high chemoselectivity for the solvent-free hydrogenation of a variety of substituted nitroarenes including the reducible functional groups to the corresponding aromatic amines under mild reaction conditions. Taking nitrobenzene as an example, the Pd/CeO2 catalyst can afford aniline yields of >99 % with turnover frequencies as high as 11 411 h?1 and 69 824 h?1 at 40 °C and 100 °C, respectively. Pd2+ ion species exist as isolated single atoms with ?Pd2+?O2??Ce4+? linkages on the surface of PdxCe1?xO2?σ solid solution and are found to be active sites for the selective hydrogenation of nitroarenes in the absence of solvent. The superior catalytic performance can be attributed to the cooperative effect between Pd2+ ions and unique surface sites of CeO2. A possible mechanism is proposed for the hydrogenation of nitroarenes with H2 over the Pd/CeO2. The Pd/CeO2 catalyst can be recovered easily and reused for at least seven recycling reactions without loss of catalytic properties.
Under the conditions of a solvent-free method of hydrogenation to synthesize haloarylamine
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Paragraph 0050-0053, (2017/03/21)
The invention provides a method for synthesising halogenated aromatic amine through hydrogenation in a solvent-free condition. The method comprises the following step of: carrying out a liquid-phase hydrogenation reaction on the halogenated aromatic nitro compound shown in formula (I) under the action of hydrogen, in the absence of a solvent and a dehalogenation inhibitor under the action of a carbon-supported large-particle-size precious metal catalyst to prepare the halogenated aromatic amine shown in formula (II). The method provided by the invention is capable of achieving the effect of inhibiting a hydrogenation dehalogenation side reaction in the case of not adding a dehalogenation inhibitor, is high in target product selectivity, and is capable of remarkably increasing the reaction speed.
Highly selective transfer hydrogenation of functionalised nitroarenes using cobalt-based nanocatalysts
Jagadeesh, Rajenahally V.,Banerjee, Debasis,Arockiam, Percia Beatrice,Junge, Henrik,Junge, Kathrin,Pohl, Marga-Martina,Radnik, J?rg,Brückner, Angelika,Beller, Matthias
supporting information, p. 898 - 902 (2015/03/04)
Anilines are important feedstock for the synthesis of a variety of chemicals such as dyes, pigments, pharmaceuticals and agrochemicals. The chemoselective catalytic reduction of nitro compounds represents the most important and prevalent process for the manufacture of functionalized anilines. Consequently, the development of selective catalysts for the reduction of nitro compounds in the presence of other reducible groups is a major challenge and is crucial. In this regard, herein we show that the cobalt oxide (Co3O4-NGr@C) based nano-materials, prepared by the pyrolysis of cobalt-phenanthroline complexes on carbon constitute highly selective catalysts for the transfer hydrogenation of nitroarenes to anilines using formic acid as a hydrogen source. Applying these catalysts, a series of structurally diverse and functionalized nitroarenes have been reduced to anilines with unprecedented chemo-selectivity tolerating halides, olefins, aldehyde, ketone, ester, amide and nitrile functionalities.
Nitrogen-doped graphene-activated iron-oxide-based nanocatalysts for selective transfer hydrogenation of nitroarenes
Jagadeesh, Rajenahally V.,Natte, Kishore,Junge, Henrik,Beller, Matthias
, p. 1526 - 1529 (2015/03/14)
Nanoscaled iron oxides on carbon were modified with nitrogen-doped graphene (NGr) and found to be excellent catalysts for the chemoselective transfer hydrogenation of nitroarenes to anilines. Under standard reaction conditions, a variety of functionalized and structurally diverse anilines, which serve as key building blocks and central intermediates for fine and bulk chemicals, were synthesized in good to excellent yields.
