85404-22-4Relevant articles and documents
Characteristics of Si-Y mixed oxide supported nickel catalysts for the reductive amination of ethanol to ethylamines
Jeong, Ye-Seul,Woo, Yesol,Park, Myung-June,Shin, Chae-Ho
, p. 287 - 297 (2019/10/14)
Si-Y mixed oxide synthesis was achieved via Si dissolution from a Pyrex reactor during the synthesis of yttrium hydroxide by the precipitation method at pH 10 and an aging temperature of 100 ℃. The Ni/SY mixed oxide catalysts with 5–25 wt% Ni contents were synthesized using an incipient wetness impregnation method. The characterization of the calcined Ni/SY oxide catalysts was performed using N2-sorption, X-ray diffraction, H2-temperature programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), and ethanol-TPD. The reaction parameters such as reaction temperature and the partial pressures of ethanol, NH3, and H2 were varied in the reductive amination reaction, and the catalytic activities for the production of monoethylamine, diethylamine, triethylamine, and acetonitrile as main products were compared. The 10 wt% Ni/SY oxide catalyst containing 11 wt% Si showed the maximum activity, and the presence and absence of H2 and NH3 had a great effect on the conversion and selectivities. The stability after 110 h on stream was observed to be 2.5% less than the initial activity. The cause of this deactivation is the formation of nickel carbonitride, as confirmed by XPS and temperature programmed oxidation (TPO) measurements. On the basis of a detailed proposed reaction mechanism, reaction rates were determined, and the kinetic parameters were estimated by fitting the experimental data obtained under a variety of conditions. Our kinetic model showed that the temperature and the partial pressures of ethanol and hydrogen significantly influenced the conversion, whereas the partial pressure of ammonia had little influence because the imine partial pressure rapidly reached saturation.
MOF-Derived Cu-Nanoparticle Embedded in Porous Carbon for the Efficient Hydrogenation of Nitroaromatic Compounds
Qiao, Chenxia,Jia, Wenlan,Zhong, Qiming,Liu, Bingyu,Zhang, Yifu,Meng, Changgong,Tian, Fuping
, p. 3394 - 3401 (2020/05/19)
Abstract: Novel Cu-nanoparticles (NPs) embedded in porous carbon materials (Cu@C-x) were prepared by one-pot pyrolysis of metal–organic frameworks (MOF) HKUST-1 at different temperatures. The obtained material Cu@C-x was used as a cost-effective catalyst for the hydrogenation of nitrobenzene using NaBH4 as the reducing agent under mild reaction conditions. By considering the catalyst preparation and the catalytic activity, a pyrolysis temperature of 400?°C was finally chosen to synthesize the optimal catalyst. When the aromatic nitro compounds with reducible groups, such as cyano, halogen, and alkyl groups, were tested in this catalytic hydrogenation, an excellent selectivity approaching 100% was achieved. In the recycling experiment, a significant decrease in nitrobenzene conversion was observed in the third cycle, mainly due to the very small amount of catalyst employed in the reaction. Hence, the easily prepared and cost-effective Cu@C-400 catalyst fabricated in this study demonstrates potential for the applications in selective reduction of aromatic nitro compounds. Graphic Abstract: The catalyst Cu@C-400 exhibited 100?% conversion and high selectivity for the hydrogenation of industrially relevant nitroarenes.[Figure not available: see fulltext.].
Metal-free nitrogen -doped carbon nanosheets: A catalyst for the direct synthesis of imines under mild conditions
Wang, Kaizhi,Jiang, Pengbo,Yang, Ming,Ma, Ping,Qin, Jiaheng,Huang, Xiaokang,Ma, Lei,Li, Rong
, p. 2448 - 2461 (2019/05/17)
Herein, a highly stable, porous, multifunctional and metal-free catalyst was developed, which exhibited significant catalytic performance in the oxidation of amines and transfer hydrogenation of nitriles under mild conditions; this could be attributed to the presence of numerous active sites and their outstanding BET surface area. The obtained results showed that most of the yields of imines exceeded 90%, and the cycling performance of the catalyst could be at least seven runs without any decay in the reaction activity, which could be comparable to those of metal catalysts. Subsequently, a kinetic study has demonstrated that the apparent activation energy for the direct synthesis of imines from amines is 67.39 kJ mol-1, which has been performed to testify that the catalytic performances are rational. Via catalyst characterizations and experimental data, graphitic-N has been proven to be the active site of the catalyst. Hence, this study is beneficial to comprehend the mechanism of action of a metal-free N-doped carbon catalyst in the formation of imines.
A ppm level Rh-based composite as an ecofriendly catalyst for transfer hydrogenation of nitriles: Triple guarantee of selectivity for primary amines
Liu, Lei,Li, Jifan,Ai, Yongjian,Liu, Yuhong,Xiong, Jialiang,Wang, Hongdong,Qiao, Yijun,Liu, Wenrui,Tan, Shanchao,Feng, Shaofei,Wang, Kunpeng,Sun, Hongbin,Liang, Qionglin
, p. 1390 - 1395 (2019/03/26)
Hydrogenation of nitriles to afford amines under mild conditions is a challenging task with an inexpensive heterogeneous catalyst, and it is even more difficult to obtain primary amines selectively because of the accompanying self-coupling side reactions. An efficient catalytic system was designed as Fe3O4@nSiO2-NH2-RhCu@mSiO2 to prepare primary amines through the transfer hydrogenation of nitrile compounds with economical HCOOH as the hydrogen donor. The loading of rhodium in the catalyst could be at the ppm level, and the TOF reaches 6803 h-1 for Rh. This catalytic system has a wide substrate range including some nitriles that could not proceed in the previous literature. The experimental results demonstrate that the excellent selectivity for primary amines is guaranteed by three tactics, which are the strong active site, the inhibition of side products by the hydrogen source and the special pore structure of the catalyst. In addition, the catalyst could be reused ten times without activity loss through convenient magnetic recovery.
Cobalt-based molecular electrocatalysis of nitrile reduction: Evolving sustainability beyond hydrogen
Child, Simon N.,Raychev, Radoslav,Moss, Nathan,Howchen, Benjamin,Horton, Peter N.,Prior, Christopher C.,Oganesyan, Vasily S.,Fielden, John
, p. 9576 - 9580 (2019/07/10)
Two new cobalt bis-iminopyridines, [Co(DDP)(H2O)2](NO3)2 (1, DDP = cis-[1,3-bis(2-pyridinylenamine)] cyclohexane) and [Co(cis-DDOP)(NO3)](NO3) (2, cis-DDOP = cis-3,5-bis[(2-Pyridinyleneamin]-trans-hydroxycyclohexane) electrocatalyse the 4-proton, 4-electron reduction of acetonitrile to ethylamine. For 1, this reduction occurs in preference to reduction of protons to H2. A coordinating hydroxyl proton relay in 2 reduces the yield of ethylamine and biases the catalytic system back towards H2.
Bench-Stable Cobalt Pre-Catalysts for Mild Hydrosilative Reduction of Tertiary Amides to Amines and Beyond
Nurseiit, Alibek,Janabel, Jaysan,Gudun, Kristina A.,Kassymbek, Aishabibi,Segizbayev, Medet,Seilkhanov, Tulegen M.,Khalimon, Andrey Y.
, p. 790 - 798 (2019/01/09)
The readily synthesized and bench-stable cobalt dichloride complex (dpephos)CoCl2 is employed as a pre-catalyst for a diversity of silane additions to unsaturated organic molecules, including the normally challenging reduction of amides to amines. With regard to hydrosilative reduction of amides even more effective and activator free catalytic systems can be generated from the bench-stable, commercially available Co(acac)2 and Co(OAc)2 with dpephos and PPh3 ligands. These systems operate under mild conditions (100 °C), with many examples of room temperature transformations, presenting a first example of mild cobalt-catalyzed hydrosilylation of amides.
Method of preparation of ethylamine or acetonitrile by reductive amination of ethanol
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Paragraph 0095-0099; 0107; 0144, (2019/06/22)
The present invention relates to a catalyst for manufacturing ethylamine and a method for manufacturing the same. More specifically, the present invention relates to: a nickel-supported catalyst for manufacturing ethylamine or acetonitrile which has impregnated nickel on a supporter as a catalyst capable of efficiently manufacturing ethylamine or acetonitrile at a normal pressure or lower by reacting ethanol with ammonia, a method for manufacturing the same, and a method for manufacturing ethylamine using the same.COPYRIGHT KIPO 2019
Organocatalytic Decarboxylation of Amino Acids as a Route to Bio-based Amines and Amides
Claes, Laurens,Janssen, Michiel,De Vos, Dirk E.
, p. 4297 - 4306 (2019/08/26)
Amino acids obtained by fermentation or recovered from protein waste hydrolysates represent an excellent renewable resource for the production of bio-based chemicals. In an attempt to recycle both carbon and nitrogen, we report here on a chemocatalytic, metal-free approach for decarboxylation of amino acids, thereby providing a direct access to primary amines. In the presence of a carbonyl compound the amino acid is temporarily trapped into a Schiff base, from which the elimination of CO2 may proceed more easily. After evaluating different types of aldehydes and ketones on their activity at low catalyst loadings (≤5 mol%), isophorone was identified as powerful organocatalyst under mild conditions. After optimisation many amino acids with a neutral side chain were converted in 28–99 % yield in 2-propanol at 150 °C. When the reaction is performed in DMF, the amine is susceptible to N-formylation. This consecutive reaction is catalysed by the acidity of the amino acid reactant itself. In this way, many amino acids were efficiently transformed to the corresponding formamides in a one-pot catalytic system.
Sustainable hydrogenation of aliphatic acyclic primary amides to primary amines with recyclable heterogeneous ruthenium-tungsten catalysts
Coeck, Robin,Berden, Sarah,De Vos, Dirk E.
supporting information, p. 5326 - 5335 (2019/10/11)
The hydrogenation of amides is a straightforward method to produce (possibly bio-based) amines. However current amide hydrogenation catalysts have only been validated in a rather limited range of toxic solvents and the hydrogenation of aliphatic (acyclic) primary amides has rarely been investigated. Here, we report the use of a new and relatively cheap ruthenium-tungsten bimetallic catalyst in the green and benign solvent cyclopentyl methyl ether (CPME). Besides the effect of the Lewis acid promotor, NH3 partial pressure is identified as the key parameter leading to high primary amine yields. In our model reaction with hexanamide, yields of up to 83% hexylamine could be achieved. Beside the NH3 partial pressure, we investigated the effect of the catalyst support, PGM-Lewis acid ratio, H2 pressure, temperature, solvent tolerance and product stability. Finally, the catalyst was characterized and proven to be very stable and highly suitable for the hydrogenation of a broad range of amides.
Alkyl coupling in tertiary amines as analog of Guerbet condensation reaction
Zhou, Yage,Wu, Dan,Hernández, Willinton Yesid,Ma, Changru,Su, Huangyang,Ordomsky, Vitaly
, p. 9845 - 9849 (2019/04/01)
We report here that C-C coupling in tertiary amines for the synthesis of long chain and hindered amines might be efficiently performed over Pt and Pd catalysts. The mechanism study confirms similarity with the Guerbet reaction through dehydrogenation of the alkyl group and subsequent attack of the α-carbon atom by an alkyl group of another molecule. Finally, secondary amines and tertiary amines with longer alkyl chains are formed.
