- General and selective synthesis of primary amines using Ni-based homogeneous catalysts
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The development of base metal catalysts for industrially relevant amination and hydrogenation reactions by applying abundant and atom economical reagents continues to be important for the cost-effective and sustainable synthesis of amines which represent highly essential chemicals. In particular, the synthesis of primary amines is of central importance because these compounds serve as key precursors and central intermediates to produce value-added fine and bulk chemicals as well as pharmaceuticals, agrochemicals and materials. Here we report a Ni-triphos complex as the first Ni-based homogeneous catalyst for both reductive amination of carbonyl compounds with ammonia and hydrogenation of nitroarenes to prepare all kinds of primary amines. Remarkably, this Ni-complex enabled the synthesis of functionalized and structurally diverse benzylic, heterocyclic and aliphatic linear and branched primary amines as well as aromatic primary amines starting from inexpensive and easily accessible carbonyl compounds (aldehydes and ketones) and nitroarenes using ammonia and molecular hydrogen. This Ni-catalyzed reductive amination methodology has been applied for the amination of more complex pharmaceuticals and steroid derivatives. Detailed DFT computations have been performed for the Ni-triphos based reductive amination reaction, and they revealed that the overall reaction has an inner-sphere mechanism with H2metathesis as the rate-determining step.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Jiao, Haijun,Murugesan, Kathiravan,Wei, Zhihong
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p. 4332 - 4339
(2020/05/18)
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- Ultra-small cobalt nanoparticles from molecularly-defined Co-salen complexes for catalytic synthesis of amines
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We report the synthesis of in situ generated cobalt nanoparticles from molecularly defined complexes as efficient and selective catalysts for reductive amination reactions. In the presence of ammonia and hydrogen, cobalt-salen complexes such as cobalt(ii)-N,N′-bis(salicylidene)-1,2-phenylenediamine produce ultra-small (2-4 nm) cobalt-nanoparticles embedded in a carbon-nitrogen framework. The resulting materials constitute stable, reusable and magnetically separable catalysts, which enable the synthesis of linear and branched benzylic, heterocyclic and aliphatic primary amines from carbonyl compounds and ammonia. The isolated nanoparticles also represent excellent catalysts for the synthesis of primary, secondary as well as tertiary amines including biologically relevant N-methyl amines.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Gawande, Manoj B.,Jagadeesh, Rajenahally V.,Kalevaru, Narayana V.,Kamer, Paul C. J.,Senthamarai, Thirusangumurugan,Zbo?il, Radek
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p. 2973 - 2981
(2020/03/27)
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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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- 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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- Green and convenient protocols for the efficient reduction of nitriles and nitro compounds to corresponding amines with NaBH4 in water catalyzed by magnetically retrievable CuFe2O4 nanoparticles
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Abstract: In this study, firstly, CuFe2O4 nanoparticles were prepared by a simple operation. The structure of the mentioned nanoparticles was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma-optical emission spectrometry, vibrating sample magnetometer and also Brunauer–Emmett–Teller and Barrett–Joyner–Halenda analyses. The prepared magnetically copper ferrite nanocomposite was successfully applied as a simple, cost-effective, practicable, and recoverable catalyst on the green, highly efficient, fast, base-free, and ligand-free reduction of nitriles and also on the affordable and eco-friendly reduction of nitro compounds with the broad substrate scope to the corresponding amines with NaBH4 in water at reflux in high to excellent yields. Graphical abstract: [Figure not available: see fulltext.].
- Zeynizadeh, Behzad,Mohammad Aminzadeh, Farkhondeh,Mousavi, Hossein
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- MOF-derived cobalt nanoparticles catalyze a general synthesis of amines
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The development of base metal catalysts for the synthesis of pharmaceutically relevant compounds remains an important goal of chemical research. Here, we report that cobalt nanoparticles encapsulated by a graphitic shell are broadly effective reductive amination catalysts. Their convenient and practical preparation entailed template assembly of cobaltdiamine- dicarboxylic acid metal organic frameworks on carbon and subsequent pyrolysis under inert atmosphere.The resulting stable and reusable catalysts were active for synthesis of primary, secondary, tertiary, and N-methylamines (more than 140 examples).The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, or nitro compounds, and molecular hydrogen under industrially viable and scalable conditions, offering cost-effective access to numerous amines, amino acid derivatives, and more complex drug targets.
- Jagadeesh, Rajenahally V.,Murugesan, Kathiravan,Alshammari, Ahmad S.,Neumann, Helfried,Pohl, Marga-Martina,Radnik, J?rg,Beller, Matthias
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p. 326 - 332
(2017/09/28)
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- Design and synthesis of neolamellarin a derivatives targeting heat shock protein 90
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In this study, we designed and synthesized a novel family of neolamellarin A derivatives that showed high inhibitory activity toward heat shock protein 90 (Hsp90), a kinase associated with cell proliferation. The 3,4-bis(catechol)pyrrole scaffold and the benzyl group with methoxy modification at N position of pyrrole are essential to the Hsp90 inhibitory activity and cytotoxicity of these compounds. Western blot analysis demonstrated that these compounds induced dramatic depletion of the examined client proteins of Hsp90, and accelerated cancer cell apoptosis. Docking simulations suggested that the binding mode of 9p was similar to that of the VER49009, a potent inhibitor of Hsp90. Further molecular dynamics simulation indicated that the hydrophobic interactions as well as the hydrogen bonds contributed to the high affinity of 9p to Hsp90.
- Jiang, Long,Yin, Ruijuan,Wang, Xueting,Dai, Jiajia,Li, Jing,Jiang, Tao,Yu, Rilei
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- A method for the production of primary amines
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The invention relates to the field of chemical industry and particularly relates to a method for preparing primary amine by using the raw materials including halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) and ammonia water (or formamide). The method comprises the following three steps: (1) imidization: 3,4-diarylfuran-2,5-diketone (I) reacts with ammonia (or formamide) and the like to obtain 3,4-diaryl-1H-pyrrole-2,5-diketone (II); (2) N-hydrocarbylation: 3,4-diaryl-1H-pyrrole-2,5-diketone (II) generates an N-hydrocarbylation reaction with halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) in the presence of alkali to obtain N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III); and (3) hydrolysis: N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III) is subjected to alkali hydrolysis to obtain primary amine and the generated 2,3-diaryl maleate is subjected to acid treatment and automatic ring closing to form 3,4-diaryl furan-2,5-diketone (I) which is subjected to imidization and directly applied to the N-hydrocarbylation reaction. The method provided by the invention has the characteristics that the 3,4-diaryl furan-2,5-diketone can be circularly used at a high recovery rate, the molar ratio of the raw materials is low, and the yield of the product primary amine is high.
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Paragraph 0130
(2016/10/09)
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- Magnesium-Catalyzed Proficient Reduction of Oximes to Amines Using Ammonium Formate
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Various aldoximes and ketoximes were selectively reduced to the corresponding amines by catalytic transfer hydrogenation employing low cost magnesium powder and ammonium formate at room temperature. Many other functionalities such as halogens, -OH, -OCH3, -COOH and -CH 3 remained unaffected. The hydrogenation is fast, mild, clean, cost effective and high yielding.
- Abiraj,Gowda, D. Channe
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p. 599 - 605
(2007/10/03)
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- Zinc/ammonium formate: A new facile system for the rapid and selective reduction of oximes to amines
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Various oximes, both aldoximes and ketoximes, are selectively reduced to corresponding amines employing low cost zinc dust and ammonium formate despite presence of other functional groups such as halogens, -OH, -OCH3, -COOH, -CN, > C = C 3.
- Abiraj,Gowda, D. Channe
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p. 332 - 334
(2007/10/03)
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- 5-HT2A receptor inverse agonists
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Disclosed herein is a new class of pyrazole compounds which act at the 5HT2A receptors.
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- Small molecule modulators of non-endogenous, constitutively activated human serotonin receptors
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Disclosed herein are non-endogenous, constitutively activated forms of the human 5-HT2A and human 5-HT2C receptors and uses of such receptors to screen candidate compounds. Further disclosed herein are candidate compounds identified by the screening method which act at the 5HT2A receptors. Yet further disclosed is a new class of compounds which act at the 5HT2A receptors.
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- Method for inhibition of HIV related viruses
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Treatment of AIDS, inhibition of the replication of HIV and related viruses thereof, and formulations using thiourea derivative compounds or salts thereof is disclosed. Also disclosed are novel thiourea derivative compounds.
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