- Selective catalytic transfer hydrogenation of nitriles to primary amines using Pd/C
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The catalytic transfer hydrogenation of (hetero)aryl nitriles using ammonium formate has been investigated in detail. In the presence of commercially available Pd/C, a straightforward and selective reduction is achieved without any additives under mild conditions.
- Vilches-Herrera, Marcelo,Werkmeister, Svenja,Junge, Kathrin,Boerner, Armin,Beller, Matthias
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- Bifunctional N-Doped Co@C Catalysts for Base-Free Transfer Hydrogenations of Nitriles: Controllable Selectivity to Primary Amines vs Imines
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The transfer hydrogenation of nitriles is an important and alternative strategy to produce primary amines or imines, both of which play a crucial role in the synthesis of fine chemicals and pharmaceuticals. Nevertheless, developing highly active bifunctional catalyst system with controllable selectivity for these reactions still remains a huge challenge. In this study, we presented a bifunctional N-doped Co@C catalyst system (Co@NC) for the selective transfer hydrogenation of nitriles into either primary amines or imines. The Co@NC was prepared by the direct pyrolysis of an N-containing Co-MOF under an inert atmosphere, where the N-containing ligands could be transformed into highly graphitic N-doped carbon, endowing the catalysts with high-density special basic sites, while the Co2+ ions were reduced to uniform Co nanoparticles which were dispersed on or embedded in N-doped graphitic structures. Under base-free conditions with isopropyl alcohol as both proton donor and solvent, the optimized Co@NC-900 (obtained at 900 °C) catalyst could convert nitriles into primary amines or imines at will with surprising selectivities (mostly higher than 90%), depending on the solvent volume added to the reaction systems. Furthermore, a possible reaction mechanism was proposed. The N-derived basic sites on Co@NC could play a role similar to that of the base additives, which not only inhibit the formation of polyamine or prevent the products stacked on the surface of catalysts but also effectively promote the transfer hydrogenation of nitriles. The generated corresponding primary imines could controllably attack the primary imine intermediates to form imines by adjusting the concentration of Co@NC. It is clear that this strategy offers a high-performance catalyst system for base-free transfer hydrogenations of nitriles to selectively produce primary amines vs imines.
- Long, Jilan,Shen, Kui,Li, Yingwei
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- Turning the product selectivity of nitrile hydrogenation from primary to secondary amines by precise modification of Pd/SiC catalysts using NiO nanodots
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The selectivity of supported metal catalysts is mainly determined by the active metallic component, and thus turning the selectivity to a completely different product is rarely achieved by modification of the catalysts. Hydrogenation of nitriles is an efficient and environmentally benign route for the synthesis of valuable amines, but it usually produces mixtures of primary, secondary and even tertiary amines. Herein we report that the selectivity of Pd/SiC catalysts for the hydrogenation of nitriles with H2 can be turned from primary to secondary amines by modification of NiO nanodots. In the modified catalysts, the NiO nanodots act as reactive sites to consume hydrogen radicals on the Pd surface, and thus prolong the lifetime of an imine intermediate that determines the product selectivity. Under mild conditions (30 °C, atmospheric H2), Pd/SiC and NiO-Pd/SiC catalysts exhibit high selectivity to primary (94%) and secondary (99%) amines, respectively.
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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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Read Online
- Cobalt-Catalyzed Hydrogenative Transformation of Nitriles
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Here, we report the transformation of nitrile compounds in a hydrogen atmosphere. Catalyzed by a cobalt/tetraphosphine complex, hydrogenative coupling of unprotected indoles with nitriles proceeds smoothly in a basic medium, yielding C3 alkylated indoles. In addition, the direct hydrogenation of nitriles under the same conditions yielded primary amines. Isotope labeling experiments, along with a series of control experiments, revealed a reaction pathway that involves nucleophilic addition of indoles and 1,4-reduction of a conjugate imine intermediate. Different from reductive alkylation of indoles under an acidic condition, E1cB elimination is believed to occur in this base-promoted hydrogenative coupling reaction.
- Zhang, Shaoke,Duan, Ya-Nan,Qian, Yu,Tang, Wenyue,Zhang, Runtong,Wen, Jialin,Zhang, Xumu
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p. 13761 - 13767
(2021/11/17)
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- Method for preparing primary amine by catalytically reducing nitrile compounds through nano-porous palladium catalyst
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The invention belongs to the technical field of heterogeneous catalysis, and provides a method for preparing primary amine by catalytically reducing nitrile compounds with a nano-porous palladium catalyst. According to the invention, aromatic and aliphatic nitrile compounds are adopted as raw materials, nano-porous palladium is adopted as a catalyst, ammonia borane is adopted as a hydrogen source, no additional additive is added, and selective hydrogenation is performed to prepare the corresponding primary amine. The method provided by the invention has the beneficial effects of mild reaction conditions, no additive, environmental protection, no need of hydrogen, simple operation, stable hydrogen source, safety, harmlessness, high conversion rate, high selectivity and good catalyst stability, and makes industrialization possible.
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Paragraph 0069-0072
(2021/05/29)
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- Generation of Oxidoreductases with Dual Alcohol Dehydrogenase and Amine Dehydrogenase Activity
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The l-lysine-?-dehydrogenase (LysEDH) from Geobacillus stearothermophilus naturally catalyzes the oxidative deamination of the ?-amino group of l-lysine. We previously engineered this enzyme to create amine dehydrogenase (AmDH) variants that possess a new hydrophobic cavity in their active site such that aromatic ketones can bind and be converted into α-chiral amines with excellent enantioselectivity. We also recently observed that LysEDH was capable of reducing aromatic aldehydes into primary alcohols. Herein, we harnessed the promiscuous alcohol dehydrogenase (ADH) activity of LysEDH to create new variants that exhibited enhanced catalytic activity for the reduction of substituted benzaldehydes and arylaliphatic aldehydes to primary alcohols. Notably, these novel engineered dehydrogenases also catalyzed the reductive amination of a variety of aldehydes and ketones with excellent enantioselectivity, thus exhibiting a dual AmDH/ADH activity. We envisioned that the catalytic bi-functionality of these enzymes could be applied for the direct conversion of alcohols into amines. As a proof-of-principle, we performed an unprecedented one-pot “hydrogen-borrowing” cascade to convert benzyl alcohol to benzylamine using a single enzyme. Conducting the same biocatalytic cascade in the presence of cofactor recycling enzymes (i.e., NADH-oxidase and formate dehydrogenase) increased the reaction yields. In summary, this work provides the first examples of enzymes showing “alcohol aminase” activity.
- Tseliou, Vasilis,Schilder, Don,Masman, Marcelo F.,Knaus, Tanja,Mutti, Francesco G.
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supporting information
p. 3315 - 3325
(2020/12/11)
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- Self-regulated catalysis for the selective synthesis of primary amines from carbonyl compounds
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Most current processes for the general synthesis of primary amines by reductive amination are performed with enormously excessive amounts of hazardous ammonia. It remains unclear how catalysts should be designed to regulate amination reaction dynamics at a low ammonia-to-substrate ratio for the quantitative synthesis of primary amines from the corresponding carbonyl compounds. Herein we show a facile control of the reaction selectivity in the layered boron nitride supported ruthenium catalyzed reductive amination reaction. Specifically, locating ruthenium to the edge surface of layered boron nitride leads to an increased hydrogenation activity owing to the enhanced interfacial electronic effects between ruthenium and the edge surface of boron nitride. This enables self-accelerated reductive amination reactions which quantitatively synthesize structurally diverse primary amines by reductive amination of carbonyl compounds with twofold ammonia. This journal is
- Fan, Xiaomeng,Gao, Jin,Gao, Mingxia,Jia, Xiuquan,Ma, Jiping,Xu, Jie
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supporting information
p. 7115 - 7121
(2021/09/28)
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- Half-sandwiched ruthenium complex containing carborane schiff base ligand and preparation and application thereof
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The invention relates to a half-sandwiched ruthenium complex containing a carborane schiff base ligand and a preparation and an application thereof. The preparation method specifically comprises the following steps; i) dissolving o-carborane formaldehyde and aromatic amine in an organic solvent, carrying out reaction at 60-100 DEG C for 8-12h, cooling to room temperature after the reaction; ii) adding n-butyllithium, carrying out reaction at room temperature for 1.5-2.5h; ii) adding phellandrene ruthenium chloride dimer, carrying out reaction at room temperature for 3-6h, and obtaining the half-sandwiched ruthenium complex through separation. The half-sandwiched ruthenium complex is applied to catalyze transfer hydrogenation reaction of nitrile compounds. Compared with the prior art, the complex of the present invention is not sensitive to air and water, has stable properties, and shows high-efficiency catalytic activity in catalyzing the transfer hydrogenation reaction of nitrile compounds. The preparation method of the complex is simple and green, high in yield, mild in reaction conditions and good in universality.
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Paragraph 0067-0071
(2020/12/09)
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- Benzimidazole fragment containing Mn-complex catalyzed hydrosilylation of ketones and nitriles
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The synthesis of a new bidentate (NN)–Mn(I) complex is reported and its catalytic activity towards the reduction of ketones and nitriles is studied. On comparing the reactivity of various other Mn(I) complexes supported by benzimidazole ligand, it was observed that the Mn(I) complexes bearing 6-methylpyridine and benzimidazole fragments exhibited the highest catalytic activity towards monohydrosilylation of ketones and dihydrosilylation of nitriles. Using this protocol, a wide range of ketones were selectively reduced to the corresponding silyl ethers. In case of unsaturated ketones, the chemoselective reduction of carbonyl group over olefinic bonds was observed. Additionally, selective dihydrosilylation of several nitriles were also achieved using this complex. Mechanistic investigations with radical scavengers suggested the involvement of radical species during the catalytic reaction. Stoichiometric reaction of the Mn(I) complex with phenylsilane revealed the formation of a new Mn(I) complex.
- Ganguli, Kasturi,Mandal, Adarsha,Sarkar, Bidisha,Kundu, Sabuj
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- Method for preparing primary amines through hydrogen transfer selective nitrile reduction
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The invention discloses a method for preparing primary amines through hydrogen transfer selective nitrile reduction. The method includes the step of adding low-price copper, iron and other metal saltsor low-price easy-to-obtain iodine elementary substances as additives with a nitrile compound as the raw material and oxazole borane as the hydrogen transfer agent under the mild conditions, therebypromoting the hydrogen transfer reaction and selectively synthesizing a series of corresponding primary amines under different conditions respectively. The high yield and high selectivity are achievedin the reaction. The oxazole borane is obtained through reaction of alkamine and a tetrahydrofuran complex of borane. In addition, the method is mild in reaction condition, easy to operate, free of high-pressure devices, environmentally friendly and high in raw material general applicability, the agents required for the reaction are all low in price and easy to obtain, the reduction product is only primary amines, and selectivity and repeatability are high. Thus, an effective scheme is provided for the industrial production of other high-additional-value compounds of similar structures in future.
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Paragraph 0047-0051
(2019/05/02)
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- Mild palladium-catalysed highly efficient hydrogenation of CN, C-NO2, and CO bonds using H2 of 1 atm in H2O
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Here we present the first example of a mild and high-efficiency protocol enabling a process in water using 1 atm of H2 for the efficient and selective hydrogenation of nitriles, nitro compounds, ketones, and aldehydes to yield primary amines and alcohols with satisfactory yields of up to >99%. Several palladium-based nanoparticle catalysts were prepared from K2PdCl4 and ligands, and one of them was found to be the best and most suitable for the hydrogenation of CN, C-NO2, and CO bonds. In addition, the catalyst Pd-NPs can be easily recycled and reused without losing their activity and selectivity. A plausible mechanism for the hydrogenation of a CN bond was also proposed, representing the first example that possesses great potential for sustainable industrial purposes.
- Liu, Yaxu,He, Shaopo,Quan, Ziyi,Cai, Huizhuo,Zhao, Yang,Wang, Bo
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supporting information
p. 830 - 838
(2019/02/27)
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- Nitrogen-Doped Carbon-Supported Nickel Nanoparticles: A Robust Catalyst to Bridge the Hydrogenation of Nitriles and the Reductive Amination of Carbonyl Compounds for the Synthesis of Primary Amines
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An efficient method was developed for the synthesis of primary amines either from the hydrogenation of nitriles or reductive amination of carbonyl compounds. The reactions were catalyzed by nitrogen-doped mesoporous carbon (MC)-supported nickel nanoparticles (abbreviated as MC/Ni). The MC/Ni catalyst demonstrated high catalytic activity for the hydrogenation of nitriles into primary amines in high yields (81.9–99 %) under mild reaction conditions (80 °C and 2.5 bar H2). The MC/Ni catalyst also promoted the reductive amination of carbonyl compounds for the synthesis of primary amines at 80 °C and 1 bar H2. The hydrogenation of nitriles and the reductive amination proceeded through the same intermediates for the generation of the primary amines. To the best of our knowledge, no other heterogeneous non-noble metal catalysts have been reported for the synthesis of primary amines under mild conditions, both from the hydrogenation of nitriles and reductive amination.
- Zhang, Yangmin,Yang, Hanmin,Chi, Quan,Zhang, Zehui
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p. 1246 - 1255
(2019/03/07)
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- Cobalt complex, preparation method thereof, and application thereof in selective catalysis of transfer hydrogenation reaction of cyano group
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The invention discloses a cobalt complex, a preparation method thereof, and an application thereof in the selective catalysis of a transfer hydrogenation reaction of a cyano group. The structural formula of the cobalt complex is represented by formula I. The cobalt complex is prepared through a reaction of a cobalt salt and an NNP ligand or a PNP ligand under the protection of an inert atmosphere;and the chemical formula of the cobalt salt is CoX12, wherein X1 represents halogen, a sulfate radical, a perchlorate radical, a hexafluorophosphate radical, a hexafluoroantimonate radical, a tetrafluoroborate radical, a trifluoromethanesulfonate radical or a tetra(pentafluorophenyl)borate radical. The cobalt complex can be used in the selective catalysis of the transfer hydrogenation reaction ofthe cyano group to obtain a primary amine compound, a secondary amine compound and a tertiary amine compound, the primary amine compound, the secondary amine compound and the tertiary amine compoundare important intermediates in a series of subsequent functionalizing reactions, and the cobalt complex has a very high catalysis activity, and has great research values and a great application prospect.
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Paragraph 0157-0159; 0161
(2018/05/07)
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- Highly Stable COF-Supported Co/Co(OH)2 Nanoparticles Heterogeneous Catalyst for Reduction of Nitrile/Nitro Compounds under Mild Conditions
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Ordered nanoporosity in covalent organic framework (COF) offers excellent opportunity for property development. Loading nanoparticles (nPs) onto them is one approach to introducing tailor-made properties into a COF. Here, a COF–Co/Co(OH)2 composite containing about 16 wt% of 2 nPs is prepared on a N-rich COF support that catalyzes the release of theoretical equivalence of H2 from readily available, safe, and cheap NaBH4. Furthermore, the released H2 is utilized for the hydrogenation of nitrile and nitro compounds to amines under ambient conditions in a facile one-pot reaction. The COF “by choice” is built from “methoxy” functionalized dialdehydes which is crucial in enabling the complete retention of the COF structure under the conditions of the catalysis, where the regular Schiff bonds would have hydrolyzed. The N-rich binding pockets in the COF ensure strong nP–COF interactions, which provides stability and enables catalyst recycling. Modeling studies reveal the crucial role played by the COF in exposing the active facets and thereby in controlling the activation of the reducing agent. Additionally, via density functional theory, we provide a rational explanation for how these COFs can stabilize nanoparticles which grow beyond the limiting pore size of the COF and yet result in a truly stable heterogeneous catalyst – a ubiquitous observation. The study underscores the versatility of COF as a heterogeneous support for developing cheap and highly active nonnoble metal catalysts.
- Mullangi, Dinesh,Chakraborty, Debanjan,Pradeep, Anu,Koshti, Vijay,Vinod, Chathakudath P.,Panja, Soumendranath,Nair, Sunil,Vaidhyanathan, Ramanathan
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- Cobalt-based nanoparticles prepared from MOF-carbon templates as efficient hydrogenation catalysts
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The development of efficient and selective nanostructured catalysts for industrially relevant hydrogenation reactions continues to be an actual goal of chemical research. In particular, the hydrogenation of nitriles and nitroarenes is of importance for the production of primary amines, which constitute essential feedstocks and key intermediates for advanced chemicals, life science molecules and materials. Herein, we report the preparation of graphene shell encapsulated Co3O4- and Co-nanoparticles supported on carbon by the template synthesis of cobalt-terephthalic acid MOF on carbon and subsequent pyrolysis. The resulting nanoparticles create stable and reusable catalysts for selective hydrogenation of functionalized and structurally diverse aromatic, heterocyclic and aliphatic nitriles, and as well as nitro compounds to primary amines (>65 examples). The synthetic and practical utility of this novel non-noble metal-based hydrogenation protocol is demonstrated by upscaling several reactions to multigram-scale and recycling of the catalyst.
- Murugesan, Kathiravan,Senthamarai, Thirusangumurugan,Sohail, Manzar,Alshammari, Ahmad S.,Pohl, Marga-Martina,Beller, Matthias,Jagadeesh, Rajenahally V.
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p. 8553 - 8560
(2018/11/30)
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- Direct Primary Amination of Alkylmetals with NH-Oxaziridine
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A method for the primary electrophilic amination of primary, secondary, and tertiary organometallic substrates from a bench-stable NH-oxaziridine reagent is described. This facile and highly chemoselective transformation occurs at ambient temperature and without transition metal catalysts or purification by column chromatography to provide alkylamine products in a single step. Density functional theory (DFT) calculations revealed that, despite the basicity of alkylmetals, the direct NH-transfer pathway is favored over proton and O-transfer.
- Behnke, Nicole Erin,Kielawa, Russell,Kwon, Doo-Hyun,Ess, Daniel H.,Kürti, László
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supporting information
p. 8064 - 8068
(2019/01/04)
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- Bioproduction of benzylamine from renewable feedstocks via a nine-step artificial enzyme cascade and engineered metabolic pathways
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Production of chemicals from renewable feedstocks has been an important task for sustainable chemical industry. Although microbial fermentation has been widely employed to produce many biochemicals, it is still very challenging to access non-natural chemicals. Two methods (biotransformation and fermentation) have been developed for the first bio-derived synthesis of benzylamine, a commodity non-natural amine with broad applications. Firstly, a nine-step artificial enzyme cascade was designed by biocatalytic retrosynthetic analysis and engineered in recombinant E. coli LZ243. Biotransformation of l-phenylalanine (60 mm) with the E. coli cells produced benzylamine (42 mm) in 70 % conversion. Importantly, the cascade biotransformation was scaled up to 100 mL and benzylamine was successfully isolated in 57 % yield. Secondly, an artificial biosynthesis pathway to benzylamine from glucose was developed by combining the nine-step cascade with an enhanced l-phenylalanine synthesis pathway in cells. Fermentation with E. coli LZ249 gave benzylamine in 4.3 mm concentration from glucose. In addition, one-pot syntheses of several useful benzylamines from the easily available styrenes were achieved, representing a new type of alkene transformation by formal oxidative cleavage and reductive amination.
- Zhou, Yi,Wu, Shuke,Mao, Jiwei,Li, Zhi
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p. 2221 - 2228
(2018/10/20)
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- Low-Pressure Hydrogenation of Nitriles to Primary Amines Catalyzed by Ruthenium Pincer Complexes. Scope and mechanism
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The catalytic hydrogenation of nitriles to primary amines constitutes an environmentally benign and atom-economical methodology in synthetic organic chemistry. However, selective hydrogenation can be challenging, and usually elevated pressure and the use of various additives is required. Herein the hydrogenation of aromatic and aliphatic nitriles to form primary amines catalyzed by ruthenium pincer complexes is described. The reactions are conducted at low H2 pressure, low catalytic loadings and, in case of a variety of benzonitriles, under neutral conditions and without any additives. Mechanistic insight is provided.
- Mukherjee, Arup,Srimani, Dipankar,Ben-David, Yehoshoa,Milstein, David
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p. 559 - 563
(2017/02/26)
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- Cobalt-Catalyzed and Lewis Acid-Assisted Nitrile Hydrogenation to Primary Amines: A Combined Effort
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The selective hydrogenation of nitriles to primary amines using a bench-stable cobalt precatalyst under 4 atm of H2 is reported herein. The catalyst precursor was reduced in situ using NaHBEt3, and the resulting Lewis acid formed, BEt3, was found to be integral to the observed catalysis. Mechanistic insights gleaned from para-hydrogen induced polarization (PHIP) transfer NMR studies revealed that the pairwise hydrogenation of nitriles proceeded through a Co(I/III) redox process.
- Tokmic, Kenan,Jackson, Bailey J.,Salazar, Andrea,Woods, Toby J.,Fout, Alison R.
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supporting information
p. 13554 - 13561
(2017/10/05)
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- Versatile Dynamic Covalent Assemblies for Probing π-Stacking and Chirality Induction from Homotopic Faces
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Herein we report for the first time the use of dynamic covalent reactions (DCRs) for building a π-stacking model system and further quantifying its substituent effects (SEs), which remain a topic of debate despite the rich history of stacking. A general DCR between 10-methylacridinium ion and primary amines was discovered, in which π-stacking played a stabilizing role. Facile quantification of SEs with in situ competing π-stacking systems was next achieved in the form of amine exchange exhibiting structural diversity by simply varying components. The linear correlation with σm in Hammett plots indicates the dominance of purely electrostatic SEs, and the additivity of SEs is in line with the direct interaction model. With α-chiral amines π-stacking within the adduct enabled chirality transfer from homotopic faces. The strategy of dynamic covalent assembly should be appealing to future research of probing weak interactions and manipulating chirality.
- Ye, Hebo,Hai, Yu,Ren, Yulong,You, Lei
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p. 3804 - 3809
(2017/03/27)
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- Mild and Selective Cobalt-Catalyzed Chemodivergent Transfer Hydrogenation of Nitriles
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Herein, we describe a selective cobalt-catalyzed chemodivergent transfer hydrogenation of nitriles to synthesize primary, secondary, and tertiary amines. The solvent effect plays a key role for the selectivity control. The general applicability of this procedure was highlighted by the synthesis of more than 70 amine products bearing various functional groups in high chemoselectivity. Moreover, this mild system achieved >2000 TONs (turnover numbers) for the transfer hydrogenation of nitriles.
- Shao, Zhihui,Fu, Shaomin,Wei, Mufeng,Zhou, Shaolin,Liu, Qiang
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supporting information
p. 14653 - 14657
(2016/11/23)
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- Selective hydrogenation of nitriles to primary amines catalyzed by a novel iron complex
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Hydrogenation of nitriles to primary amines constitutes an atom-efficient and environmentally benign synthetic reaction. Herein we present a novel complex based on earth-abundant iron, and its application in the catalytic homogeneous hydrogenation of (hetero)aromatic, benzylic, and aliphatic nitriles to selectively form primary amines.
- Chakraborty, Subrata,Leitus, Gregory,Milstein, David
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supporting information
p. 1812 - 1815
(2016/02/05)
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- Reductive amination of furfural toward furfurylamine with aqueous ammonia under hydrogen over Ru-supported catalyst
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Poly(N-vinyl-2-pyrrolidone)-capped ruthenium-supported hydroxyapatite (Ru-PVP/HAP) shows significant activity for the synthesis of furfurylamine (FAM) via the reductive amination of furfural. As-prepared 5 wt% Ru-PVP/HAP affords 50 % yield of FAM in 25 % NH3 aqueous solution under pressurized H2 gas (2.5 atm), and the highest yield approaches 60 % at 4.0 H2 atm. Comparison between the activities over four Ru-supported HAP catalysts prepared with different methods and the results of X-ray absorption spectroscopy suggested that the metallic Ru cluster is the active center for the reductive amination of furfural. Transmission electron microscope and inductively-coupled plasma analysis indicated that the as-prepared 5 wt% Ru-PVP/HAP catalyst possessed 4.0 wt% PVP-capped Ru clusters with average diameter of 1.7 ± 0.3 nm on HAP support. It was also demonstrated that the reductive amination approach with Ru-PVP/HAP catalyst, NH3 aq. and pressurized H2 gas has capability for transformation of aromatic aldehydes to the corresponding aromatic amines. According to these results, it is concluded that Ru(0) cluster supported on HAP will represent a suitable catalyst for widely-usable reductive amination to convert an aldehyde functionality towards an amine.
- Nishimura, Shun,Mizuhori, Kunihiko,Ebitani, Kohki
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- Stereoelectronic effects in the reaction of aromatic substrates catalysed by: Halomonas elongata transaminase and its mutants
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A transaminase from Halomonas elongata and four mutants generated by an in silico-based design were recombinantly produced in E. coli, purified and applied to the amination of mono-substituted aromatic carbonyl-derivatives. While benzaldehyde derivatives were excellent substrates, only NO2-acetophenones were transformed into the (S)-amine with a high enantioselectivity. The different behaviour of wild-type and mutated transaminases was assessed by in silico substrate binding mode studies.
- Contente, Martina Letizia,Planchestainer, Matteo,Molinari, Francesco,Paradisi, Francesca
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p. 9306 - 9311
(2016/10/13)
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- Selective Hydrogenation of Nitriles to Primary Amines Catalyzed by a Cobalt Pincer Complex
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The catalytic hydrogenation of nitriles to primary amines represents an atom-efficient and environmentally benign reduction methodology in organic chemistry. This has been accomplished in recent years mainly with precious-metal-based catalysts, with a single exception. Here we report the first homogeneous Co-catalyzed hydrogenation of nitriles to primary amines. Several (hetero)aromatic, benzylic, and aliphatic nitriles undergo hydrogenation to the corresponding primary amines in good to excellent yields under the reaction conditions.
- Mukherjee, Arup,Srimani, Dipankar,Chakraborty, Subrata,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 8888 - 8891
(2015/08/03)
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- Transfer hydrogenation of unsaturated bonds in the absence of base additives catalyzed by a cobalt-based heterogeneous catalyst
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A novel non-noble Co@C-N catalytic system has been developed for catalytic transfer hydrogenation reactions. Co@C-N was found to be highly active and selective in the hydrogenation of a variety of unsaturated bonds with isopropanol in the absence of base additives.
- Long, Jilan,Zhou, Ying,Li, Yingwei
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supporting information
p. 2331 - 2334
(2015/02/05)
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- Synthetic communications reviews: Synthesis of primary amines by one-pot reductive amination of aldehydes
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We report here a novel, one-pot, two-step reductive amination of aldehydes for the atom-economical synthesis of primary amines. The amination step has been carried out with hydroxylammonium chloride and does not require the use of a base. In the subsequent reduction step, a metal zinc/hydrochloride acid system has been used. This method is applicable to both aliphatic and aromatic aldehydes. The operational simplicity, the short reaction times, and the mild reaction conditions add to the value of this method as a practical alternative to the reductive amination of aldehydes. Copyright
- Ayedi, Mohamed Ali,Le Bigot, Yves,Ammar, Houcine,Abid, Souhir,Gharbi, Rachid El,Delmas, Michel
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p. 2127 - 2133
(2013/07/25)
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- Two iron catalysts are better than one: A general and convenient reduction of aromatic and aliphatic primary amides
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It takes two: For the reduction of amides to amines iron catalysts were developed. A combination of two different iron catalysts made possible the challenging reduction of primary amides (see picture). Copyright
- Das, Shoubhik,Wendt, Bianca,Moeller, Konstanze,Junge, Kathrin,Beller, Matthias
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supporting information; experimental part
p. 1662 - 1666
(2012/05/05)
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- PRODUCTION METHOD OF PRIMARY AMINES AND CATALYSTS FOR PRODUCING PRIMARY AMINES
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A method of producing a primary amine by the hydrogenation of a nitrile in the presence of a hydrogenation catalyst. The hydrogenation catalyst contains at least one metal selected from the group consisting of nickel, cobalt and iron. Before use in the hydrogenation of nitrile, the hydrogenation catalyst is pretreated with at least one treating agent selected from the group consisting of hydrocarbons, alcohols, ethers, esters and carbon monoxide at 150 to 500° C.
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Page/Page column 4-6
(2008/06/13)
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- Process for the preparation of amino compounds containing an aromatic ring by using a shell-type catalyst
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An aromatic dinitrile compound is hydrogenated in an amide solvent in the presence of a solid catalyst and in the absence of ammonia to produce an aromatic ring-containing amino compound by reducing at least one cyano group to aminomethyl group. The solid catalyst is a supported palladium catalyst in which palladium is substantially present on the outer surface of carrier and in a surface layer within a depth of 200 μm from the outer surface. Using such a solid catalyst, the aromatic dinitrile compound is efficiently hydrogenated to the aromatic ring-containing amino compound under mild conditions.
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Page/Page column 7-8
(2008/06/13)
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- Method for producing xylylenediamine
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A method of producing xylylenediamine of the present invention includes the steps of : subjecting a liquid mixture of phthalonitriles with liquid ammonia or a mixture of liquid ammonia and an organic solvent to a first catalytic hydrogenation treatment, thereby hydrogenating the phthalonitriles to obtain a reaction product (A), wherein a content of the liquid ammonia or the mixture of liquid ammonia and an organic solvent is 80 wt% or more; removing the liquid ammonia in the reaction product (A) to obtain a reaction product (B); subjecting the reaction product (B) to a second catalytic hydrogenation treatment, thereby hydrogenating cyanobenzylamine to obtain a reaction product (C); and distilling the reaction product (C) to purify xylylenediamine.
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Page/Page column 8
(2008/06/13)
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- 2-aminopyridine derivatives and combinatorial libraries thereof
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The present invention relates to novel 2-aminopyridine derivative compounds of the following formula: wherein R1to R5have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminopyridine derivative compounds.
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- Aminoborohydrides. 12. Novel tandem SNAr amination-reduction reactions of 2-halobenzonitriles with lithium N,N-dialkylaminoborohydrides
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A novel tandem amination-reduction reaction has been developed in which 2-(N,N-dialkylamino)benzylamines are generated from 2-halobenzonitriles and lithium N,N-dialkylaminoborohydride (LAB) reagents. These reactions are believed to occur through a tandem SNAr amination-reduction mechanism wherein the LAB reagent promotes halide displacement by the N,N-dialkylamino group, and the nitrile is subsequently reduced. This one-pot procedure is complimentary to existing synthetic methods and is an attractive synthetic tool for the nucleophilic aromatic substitution of halobenzenes with less nucleophilic amines. The (N,N-dialkylamino)benzylamine products of this reaction are easily isolated after a simple aqueous workup procedure in very good to excellent yields.
- Thomas,Collins,Cuzens,Spiciarich,Goralski,Singaram
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p. 1999 - 2004
(2007/10/03)
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- Anomals Schmidt reaction products of phenylacetic acid and derivatives
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Treatment of carboxylic acids with sodium azide in sulfuric acid normally results in decarboxylation with conversion of the carboxylic acid to an amine (the Schmidt reaction). However, many side reactions have been reported to occur, particulary in the case of α-aryl carboxylic acids, such as sulfonation, direct amination of the phenyl ring, cyclization to a lactam, and elimination of side chains to give aniline. In this study, the reactions of a variety of analogues of phenylacetic acid under given reaction conditions are examined to determine which characteristics are important in the competing side reactions. Some reactions were carried out with TEMPO free radical as a radical scavenger to investigate whether direct amination proceeds by a radical intermediate. Phenylacetic acid is shown to give an ortho-aminated diamine product instead of the para-aminated one expected from direct amination. A mechanism for this side reaction, involving cyclization to a lactam intermediate followed by further cleavage, is proposed; an analogue of the hypothetical intermediate has been isolated for biphenylacetic acids.
- Woodroofe, Carolyn C.,Zhong, Boyu,Lu, Xingliang,Silverman, Richard B.
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