157973-60-9Relevant academic research and scientific papers
N,N-Chelate nickel(II) complexes bearing Schiff base ligands as efficient hydrogenation catalysts for amine synthesis
Xu, Mengyin,Wang, Yang,Zhou, Yifeng,Yao, Zi-Jian
, (2021/12/09)
Five N, N-chelate nickel (II) complexes bearing N-(2-pyridinylmethylene)-benzylamine ligands with different substituent groups were synthesized in good yields. The nickel complexes exhibited prominent catalytic efficiency toward amine synthesis from nitro compounds by using NaBH4 or H2 as hydrogen source through two catalytic systems. Various amines with different substituents were obtained in moderate to excellent yields. All substrates with electron-donating and electron-withdrawing properties were tolerated in the two reduction systems. Given the efficient catalytic activity, broad substance scope, and mild reduction conditions, the nickel catalysts have potential applications in industrial production.
RhNPs supported onN-functionalized mesoporous silica: effect on catalyst stabilization and catalytic activity
Pulido-Díaz, Israel T.,Serrano-Maldonado, Alejandro,López-Suárez, Carlos César,Méndez-Ocampo, Pedro A.,Portales-Martínez, Benjamín,Gutiérrez-Alejandre, Aída,Salas-Martin, Karla P.,Guerrero-Ríos, Itzel
, p. 3289 - 3298 (2021/03/16)
Amine and nicotinamide groups grafted on ordered mesoporous silica (OMS) were investigated as stabilizers for RhNPs used as catalysts in the hydrogenation of several substrates, including carbonyl and aryl groups. Supported RhNPs on functionalized OMS were prepared by controlled decomposition of an organometallic precursor of rhodium under dihydrogen pressure. The resulting materials were characterized thoroughly by spectroscopic and physical techniques (FTIR, TGA, BET, SEM, TEM, EDX, XPS) to confirm the formation of spherical rhodium nanoparticles with a narrow size distribution supported on the silica surface. The use of nicotinamide functionalized OMS as a support afforded small RhNPs (2.3 ± 0.3 nm), and their size and shape were maintained after the catalyzed acetophenone hydrogenation. In contrast, amine-functionalized OMS formed RhNP aggregates after the catalytic reaction. The supported RhNPs could selectively reduce alkenyl, carbonyl, aryl and heteroaryl groups and were active in the reductive amination of phenol and morpholine, using a low concentration of the precious metal (0.07-0.18 mol%).
One-pot synthesis of cyclohexylamine and: N -aryl pyrroles via hydrogenation of nitroarenes over the Pd0.5Ru0.5-PVP catalyst
Chaudhari, Chandan,Sato, Katsutoshi,Ikeda, Yasuyuki,Terada, Kenji,Abe, Naoya,Nagaoka, Katsutoshi
supporting information, p. 9743 - 9746 (2021/06/15)
The direct synthesis of cyclohexylamine via the hydrogenation of nitrobenzene over monometallic (Pd, Ru or Rh) and bimetallic (PdxRu1-x) catalysts was studied. The Pd0.5Ru0.5-PVP catalyst was the most effective catalyst for this reaction. The catalyst can be reused and applied for the synthesis of N-aryl pyrroles and quinoxalines from nitrobenzenes.
MATERIALS COMPRISING CARBON-EMBEDDED COBALT NANOPARTICLES, PROCESSES FOR THEIR MANUFACTURE, AND USE AS HETEROGENEOUS CATALYSTS
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Page/Page column 17; 19-20, (2021/03/13)
The present invention relates to catalytically active material, comprising grains of non-graphitizing carbon with cobalt nanoparticles dispersed therein, wherein dP, the average diameter of cobalt nanoparticles in the non-graphitizing carbon grains, is in the range of 1 nm to 20 nm, D, the average distance between cobalt nanoparticles in the non-graphitizing carbon grains, is in the range of 2 nm to 150 nm, and ω, the combined total mass fraction of metal in the non-graphitizing carbon grains, is in the range of 30 wt% to 70 wt% of the total mass of the non-graphitizing carbon grains, and wherein dP, D and ω conform to the following relation: 4.5 dP / ω > D ≥ 0.25 dP / ω. The present invention, further, relates to a process for the manufacture of material according to the invention, as well as its use as a catalyst.
Development and Application of Efficient Ag-based Hydrogenation Catalysts Prepared from Rice Husk Waste
Unglaube, Felix,Kreyenschulte, Carsten Robert,Mejía, Esteban
, p. 2583 - 2591 (2021/04/09)
The development of strategies for the sustainable management and valorization of agricultural waste is of outmost importance. With this in mind, we report the use of rice husk (RH) as feedstock for the preparation of heterogeneous catalysts for hydrogenation reactions. The catalysts were prepared by impregnating the milled RH with a silver nitrate solution followed by carbothermal reduction. The composition and morphology of the prepared catalysts were fully assessed by IR, AAS, ICP-MS, XPS, XRD and STEM techniques. This novel bio-genic silver-based catalysts showed excellent activity and remarkable selectivity in the hydrogenation of nitro groups in both aromatic and aliphatic substrates, even in the presence of reactive functionalities like halogens, carbonyls, borate esters or nitriles. Recycling experiments showed that the catalysts can be easily recovered and reused multiple times without significant drop in performance and without requiring re-activation.
Rhodium-terpyridine Catalyzed Transfer Hydrogenation of Aromatic Nitro Compounds in Water
Liu, Yuxuan,Miao, Wang,Tang, Weijun,Xue, Dong,Xiao, Jianliang,Wang, Chao,Li, Changzhi
supporting information, p. 1725 - 1729 (2021/06/01)
A rhodium terpyridine complex catalyzed transfer hydrogenation of nitroarenes to anilines with i-PrOH as hydrogen source and water as solvent has been developed. The catalytic system can work at a substrate/catalyst (S/C) ratio of 2000, with a turnover frequency (TOF) up to 3360 h?1, which represents one of the most active catalytic transfer hydrogenation systems for nitroarene reduction. The catalytic system is operationally simple and the protocol could be scaled up to 20 gram scale. The water-soluble catalyst bearing a carboxyl group could be recycled 15 times without significant loss of activity.
Synthesis, Structure, and Catalytic Hydrogenation Activity of [NO]-Chelate Half-Sandwich Iridium Complexes with Schiff Base Ligands
Lv, Wen-Rui,Li, Rong-Jian,Liu, Zhen-Jiang,Jin, Yan,Yao, Zi-Jian
, p. 8181 - 8188 (2021/05/26)
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.
Highly Efficient and Chemoselective Hydrogenation of Nitro Compounds into Amines by Nitrogen-Doped Porous Carbon-Supported Co/Ni Bimetallic Nanoparticles
Shen, Zeyu,Hong, Lirui,Zheng, Baishu,Wang, Guanyu,Zhang, Beibei,Wang, Zhaoxu,Zhan, Feiyang,Shen, Shaohua,Yun, Ruirui
supporting information, p. 16834 - 16839 (2021/11/17)
A novel Co/Ni bimetallic nanoparticle supported by nitrogen-doped porous carbon (NPC), Co5/Ni@NPC-700, exhibits high conversion, chemoselectivity, and recyclability in the hydrogenation of 16 different nitro compounds into desired amines with hydrazine hydrate under mild conditions. The synergistic effects of Co/Ni bimetal nanoparticles and the NPC-supported porous honeycomb structure with more accessible active sites may be responsible for the high catalytic hydrogenation performance.
A Pod-like Core-Shell Catalyst with High Reduction Performance Under Mild Conditions
Du, Liting,He, Lei,Li, Tuanhui,Luo, Shizhou,Xu, Fagong,Yun, Ruirui,Zhan, Feiyang,Zhang, Beibei,Zheng, Baishu
, (2022/01/11)
Recent years, tubular structure as the carrier loading nanoparticles has been reported more and more frequently which is synthesized by pyrolysis polyhedral MOFs. However, the construct mechanism has not been referred. Herein, a tubular structure has been designed by calcining modified ZIF-8 under different temperature to reveal the formation process of tubular carbon from the polyhedron. As a result, a pod-like core-shell catalyst of Fe/Fe3C-900 has been obtained and exhibits a high activity and excellent substituent tolerance for the reduction of nitro groups under mild conditions.
Ceria supported Ru0-Ruδ+ clusters as efficient catalyst for arenes hydrogenation
Cao, Yanwei,Zheng, Huan,Zhu, Gangli,Wu, Haihong,He, Lin
supporting information, p. 770 - 774 (2020/08/24)
Selective hydrogenation of aromatic amines, especially chemicals such as aniline and bis(4-aminocyclohexyl)methane for non-yellowing polyurethane, is of particular interests due to the extensive applications. To conquer the existing difficulties in selective hydrogenation, the Ru0-Ruδ+/CeO2 catalyst with solid frustrated Lewis pairs was developed for aromatic amines hydrogenation with excellent activity and selectivity under relative milder conditions. The morphology, electronic and chemical properties, especially the Ru0-Ruδ+ clusters and reducible ceria were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), CO2 temperature programmed desorption (CO2-TPD), H2 temperature programmed reduction (H2-TPR), H2 diffuse reflectance Fourier transform infrared spectroscopy (H2-DRIFT), Raman, etc. The 2% Ru/CeO2 catalyst exhibited good conversion of 95% and selectivity greater than 99% toward cyclohexylamine. The volcano curve describing the activity and Ru state was found. Owning to the “acidic site isolation” by surrounding alkaline sites, condensation between the neighboring amine molecules could be effectively suppressed. The catalyst also showed good stability and applicability for other aromatic amines and heteroarenes containing different functional groups.
