- Selective catalysis for the reductive amination of furfural toward furfurylamine by graphene-co-shelled cobalt nanoparticles
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Amines with functional groups are widely used in the manufacture of pharmaceuticals, agricultural chemicals, and polymers but most of them are still prepared through petrochemical routes. The sustainable production of amines from renewable resources, such as biomass, is thus necessary. For this reason, we developed an eco-friendly, simplified, and highly effective procedure for the preparation of a non-toxic heterogeneous catalyst based on earth-abundant metals, whose catalytic activity on the reductive amination of furfural or other derivatives (more than 24 examples) proved to be broadly available. More surprisingly, the cobalt-supported catalyst was found to be magnetically recoverable and reusable up to eight times with an excellent catalytic activity; on the other hand, the gram-scale tests catalyzed by the same catalyst exhibited the similar yield of the target products in comparison to its smaller scale, which was comparable to the commercial noble-based catalysts. Further results from a series of analytical technologies involving XRD, XPS, TEM/mapping, and in situ FTIR revealed that the structural features of the catalyst are closely in relation to its catalytic mechanisms. In simple terms, the outer graphitic shell is activated by the electronic interaction as well as the induced charge redistribution, enabling the easy substitution of the –NH2 moiety toward functionalized and structurally diverse molecules, even under very mild industrially viable and scalable conditions. Overall, this newly developed catalyst introduces the synthesis of amines from biomass-derived platforms with satisfactory selectivity and carbon balance, providing cost-effective and sustainable access to the wide applications of reductive amination.
- Liu, Jianguo,Ma, Longlong,Zhong, Shurong,Zhuang, Xiuzheng
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p. 271 - 284
(2022/01/19)
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- Method for preparing primary amine by catalyzing reductive amination of aldehyde ketone compounds
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The invention discloses a method for preparing primary amine by catalyzing reductive amination of aldehyde ketone compounds. The method comprises the following steps: 1) mixing nickel nitrate hexahydrate, citric acid and an organic solvent, carrying out heating and stirring until a colloidal material is obtained, drying the colloidal material, roasting the colloidal material in a protective atmosphere, pickling, washing and drying a roasted product, and performing a partial oxidation reaction on a dried product in an oxygen-nitrogen mixed atmosphere to obtain a catalyst for a reductive amination reaction; and 2) mixing aldehyde or ketone compounds, a methanol solution of ammonia and the reductive amination reaction catalyst, introducing hydrogen, and carrying out a reductive amination reaction. The method has the advantages of high primary amine yield, high selectivity, wide aldehyde ketone substrate range, short reaction time, mild reaction conditions, low cost, greenness, economicalperformance and the like; the used reductive amination reaction catalyst can be recycled more than 10 times, and the catalytic activity of the catalyst is not obviously changed in gram-level reactions; and the method is suitable for large-scale application.
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Paragraph 0027-0030; 0051-0055
(2020/05/30)
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- Facile synthesis of controllable graphene-co-shelled reusable Ni/NiO nanoparticles and their application in the synthesis of amines under mild conditions
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The primary objective of many researchers in chemical synthesis is the development of recyclable and easily accessible catalysts. These catalysts should preferably be made from Earth-abundant metals and have the ability to be utilised in the synthesis of pharmaceutically important compounds. Amines are classified as privileged compounds, and are used extensively in the fine and bulk chemical industries, as well as in pharmaceutical and materials research. In many laboratories and in industry, transition metal catalysed reductive amination of carbonyl compounds is performed using predominantly ammonia and H2. However, these reactions usually require precious metal-based catalysts or RANEY nickel, and require harsh reaction conditions and yield low selectivity for the desired products. Herein, we describe a simple and environmentally friendly method for the preparation of thin graphene spheres that encapsulate uniform Ni/NiO nanoalloy catalysts (Ni/NiO?C) using nickel citrate as the precursor. The resulting catalysts are stable and reusable and were successfully used for the synthesis of primary, secondary, tertiary, and N-methylamines (more than 62 examples). The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, and H2 under very mild industrially viable and scalable conditions (80 °C and 1 MPa H2 pressure, 4 h), offering cost-effective access to numerous functionalized, structurally diverse linear and branched benzylic, heterocyclic, and aliphatic amines including drugs and steroid derivatives. We have also demonstrated the scale-up of the heterogeneous amination protocol to gram-scale synthesis. Furthermore, the catalyst can be immobilized on a magnetic stirring bar and be conveniently recycled up to five times without any significant loss of catalytic activity and selectivity for the product.
- Cui, Zhibing,Liu, Jianguo,Liu, Qiying,Ma, Longlong,Singh, Thishana,Wang, Chenguang,Wang, Nan,Zhu, Yuting
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supporting information
p. 7387 - 7397
(2020/11/19)
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- A ppm level Rh-based composite as an ecofriendly catalyst for transfer hydrogenation of nitriles: Triple guarantee of selectivity for primary amines
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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.
- 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
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p. 1390 - 1395
(2019/03/26)
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- Preparation of a magnetic mesoporous Fe3O4-Pd@TiO2 photocatalyst for the efficient selective reduction of aromatic cyanides
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Herein, a hierarchical magnetic mesoporous microsphere was successfully prepared as a photocatalyst via a simple and reproducible route. Typically, Pd nanoparticles (NPs) were evenly dispersed on the surface of a magnetic Fe3O4 microsphere and then coated with a porous anatase-TiO2 shell to form Fe3O4-Pd@TiO2. The core-shell structure could efficiently suppress the conglomeration of Pd NPs during the calcination process at high temperatures as well as the shedding of Pd during the catalytic reaction process in the liquid phase. The as-prepared photocatalyst was characterized by TEM, XRD, XPS, VSM, and N2 adsorption-desorption. Fe3O4-Pd@TiO2 exhibits high photocatalytic activity for the selective reduction of aromatic cyanides to aromatic primary amines in an acidic aqueous solution. Moreover, this magnetic photocatalyst could be easily recovered from the reaction mixture by an external magnet and reused five times without significant reduction in its activity. The superior photocatalytic efficiency of the proposed photocatalyst may be attributed to its high charge separation efficiency and charge transfer rate, which are caused by the Schottky junction and large interface area. The results indicate that the strategy of coating the active noble metal sites with a mesoporous semiconductor shell has a significant potential for application in metal-semiconductor-based photocatalytic reactions.
- Zhao, Ziming,Long, Yu,Luo, Sha,Wu, Wei,Ma, Jiantai
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p. 6294 - 6302
(2019/04/25)
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- One-pot primary aminomethylation of aryl and heteroaryl halides with sodium phthalimidomethyltrifluoroborate
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A one-pot primary aminomethylation of aryl halides, triflates, mesylates, and tosylates via Suzuki-Miyaura cross-coupling reactions with sodium phthalimidomethyltrifluoroborate followed by deamidation with ethylenediamine is reported.
- Murai, Norio,Miyano, Masayuki,Yonaga, Masahiro,Tanaka, Keigo
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p. 2818 - 2821
(2012/07/17)
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- Arylalkylamine vanadium (V) salts for the treatment and/or prevention of Diabetes mellitus
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This invention provides compounds of formula (IIA) and pharmaceutical compositions thereof, where M, a, b, and R1-R5 are as defined herein, for treating human type 1 and type 2 diabetes, particularly insulin-resistant diabetes. Pharmaceutical compositions comprising the compounds of formula (IIA) are also disclosed.
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Page/Page column 19; 20
(2010/11/26)
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- New efficient substrates for semicarbazide-sensitive amine oxidase/VAP-1 enzyme: Analysis by SARs and computational docking
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Structure activity relationships for semicarbazide-sensitive amine oxidase/vascular adhesion protein-1 (SSAO/VAP-1) were studied using a library of arylalkylamine substrates, with the aim of contributing to the discovery of more efficient SSAO substrates. Experimental data were contrasted with computational docking studies, thereby allowing us to examine the mechanism and substrate-binding affinity of SSAO and thus contribute to the discovery of more efficient SSAO substrates and provide a structural basis for their interactions. We also built a model of the mouse SSAO structure, which provides several structural rationales for interspecies differences in SSAO substrate selectivity and reveals new trends in SSAO substrate recognition. In this context, we identified novel efficient substrates for human SSAO that can be used as a lead for the discovery of antidiabetic agents.
- Yraola, Francesc,García-Vicente, Silvia,Fernández-Recio, Juan,Albericio, Fernando,Zorzano, Antonio,Marti, Luc,Royo, Miriam
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p. 6197 - 6208
(2007/10/03)
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- 2-aminobenzoxazole derivatives and combinatorial libraries thereof
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The present invention relates to novel 2-aminobenzoxazole derivative compounds of the following formula: wherein R1 to R4 and Z have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminobenzoxazole derivative compounds.
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- Synthesis and activity of 5-(aminomethylene)-1,3-cyclohexanediones: Enolic analogues of γ-aminobutyric acid
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Eight 1,3-cyclohexanediones with an aminoalkyl side chain in the 5-position were synthesized as rigid enolic analogues of GABA (γ-aminobutyric acid). Biochemical investigations about their abilities to displace [3H]GABA and [3H]baclo
- Mann,Humblet,Chambon,Schlichter,Desarmenien,Feltz,Wermuth
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p. 1440 - 1446
(2007/10/02)
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