2393-23-9Relevant articles and documents
Hydroboration of Nitriles, Esters, and Carbonates Catalyzed by Simple Earth-Abundant Metal Triflate Salts
Thenarukandiyil, Ranjeesh,Satheesh, Vanaparthi,Shimon, Linda J. W.,de Ruiter, Graham
, p. 999 - 1006 (2021/03/30)
During the past decade earth-abundant metals have become increasingly important in homogeneous catalysis. One of the reactions in which earth-abundant metals have found important applications is the hydroboration of unsaturated C?C and C?X bonds (X=O or N). Within these set of transformations, the hydroboration of challenging substrates such as nitriles, carbonates and esters still remain difficult and often relies on elaborate ligand designs and highly reactive catalysts (e. g., metal alkyls/hydrides). Here we report an effective methodology for the hydroboration of challenging C≡N and C=O bonds that is simple and applicable to a wide set of substrates. The methodology is based on using a manganese(II) triflate salt that, in combination with commercially available potassium tert-butoxide and pinacolborane, catalyzes the hydroboration of nitriles, carbonates, and esters at room temperature and with near quantitative yields in less than three hours. Additional studies demonstrated that other earth-abundant metal triflate salts can facilitate this reaction as well, which is further discussed in this report.
Deoxygenative hydroboration of primary, secondary, and tertiary amides: Catalyst-free synthesis of various substituted amines
An, Duk Keun,Jaladi, Ashok Kumar,Kim, Hyun Tae,Yi, Jaeeun
, (2021/11/17)
Transformation of relatively less reactive functional groups under catalyst-free conditions is an interesting aspect and requires a typical protocol. Herein, we report the synthesis of various primary, secondary, and tertiary amines through hydroboration of amides using pinacolborane under catalyst-free and solvent-free conditions. The deoxygenative hydroboration of primary and secondary amides proceeded with excellent conversions. The comparatively less reactive tertiary amides were also converted to the corresponding N,N-diamines in moderate yields under catalyst-free conditions, although alcohols were obtained as a minor product.
Preparation method of P-methoxybenzyl amine
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Paragraph 0025-0029, (2021/11/26)
To the method, methoxybenzaldehyde is dissolved in a solvent, a nickel-containing ternary catalyst is added, liquid ammonia is added under stirring, and hydrogen is added to carry out catalytic hydrogenation reaction. The reaction was isolated by distillation to obtain methoxybenzyl amine. The method has the characteristics of mild and safe reaction conditions, simple operation, less side reaction, high purity, high yield, and cost, good quality and the like, and has wide application prospects.
Self-regulated catalysis for the selective synthesis of primary amines from carbonyl compounds
Fan, Xiaomeng,Gao, Jin,Gao, Mingxia,Jia, Xiuquan,Ma, Jiping,Xu, Jie
supporting information, p. 7115 - 7121 (2021/09/28)
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
Comparative account of catalytic activity of Ru- and Ni-based nanocomposites towards reductive amination of biomass derived molecules
Bhanage, Bhalchandra M.,Gokhale, Tejas A.,Raut, Amol B.
, (2021/06/18)
This work includes an effective comparison of metallic ruthenium and nickel nanoparticles loaded on montmorillonite clay (MMT) for reductive amination reaction of biomass-derived molecules. It comprises an eco-friendly reaction using water as a solvent, utilizing molecular hydrogen and liquor ammonia (25% aq. solution) for the synthesis of primary amines from bio-derived aldehydes within 3–10 h of reaction time. Various parameters such as temperature, hydrogen pressure, substrate/ammonia concentration ratio, and reaction time were optimized while comparing the selectivity of primary amines for both catalysts. The applicability scope of these catalysts was explored with a library of aryl and heterocyclic aldehydes. The reductive amination of crude furfural extracted from biomass feedstock (rice husk) and pure xylose sugar was tested, showing yields in the range of 11–36%, to show the wider industrial scope of both nanocomposites. Gram scale conversion was also carried out to showcase the bulk scalability of the Ru/MMT catalyst.
Simplified preparation of a graphene-co-shelled Ni/NiO@C nano-catalyst and its application in theN-dimethylation synthesis of amines under mild conditions
Liu, Jianguo,Ma, Longlong,Song, Yanpei,Zhang, Mingyue,Zhuang, Xiuzheng
supporting information, p. 4604 - 4617 (2021/06/30)
The development of Earth-abundant, reusable and non-toxic heterogeneous catalysts to be applied in the pharmaceutical industry for bio-active relevant compound synthesis remains an important goal of general chemical research.N-methylated compounds, as one of the most essential bioactive compounds, have been widely used in the fine and bulk chemical industries for the production of high-value chemicals. Herein, an environmentally friendly and simplified method for the preparation of graphene encapsulated Ni/NiO nanoalloy catalysts (Ni/NiO@C) was developed for the first time, for the highly selective synthesis ofN-methylated compounds using various functional amines and aldehydes under easy to handle, and industrially applicable conditions. A large number of primary and secondary amines (more than 70 examples) could be converted to the correspondingN,N-dimethylamines with the participation of different functional aldehydes, with an average yield of over 95%. A gram-scale synthesis also demonstrated a similar yield when compared with the benchmark test. In addition, it was further proved that the catalyst could easily be recycled because of its intrinsic magnetism and reused up to 10 times without losing its activity and selectivity. Also, for the first time, the tandem synthesis ofN,N-dimethylamine products in a one-pot process, using only a single earth-abundant metal catalyst, whose activity and selectivity were more than 99% and 94%, respectively, for all tested substrates, was developed. Overall, the advantages of this newly developed method include operational simplicity, high stability, easy recyclability, cost-effectiveness of the catalyst, and good functional group compatibility for the synthesis ofN-methylation products as well as the industrially applicable tandem synthesis process.
Method for preparing primary amine by catalytically reducing nitrile compounds through nano-porous palladium catalyst
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Paragraph 0073-0076, (2021/05/29)
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.
Cobalt-Catalyzed Hydrogenative Transformation of Nitriles
Zhang, Shaoke,Duan, Ya-Nan,Qian, Yu,Tang, Wenyue,Zhang, Runtong,Wen, Jialin,Zhang, Xumu
, p. 13761 - 13767 (2021/11/17)
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.
Zirconium-hydride-catalyzed site-selective hydroboration of amides for the synthesis of amines: Mechanism, scope, and application
Han, Bo,Jiao, Haijun,Wu, Lipeng,Zhang, Jiong
, p. 2059 - 2067 (2021/09/02)
Developing mild and efficient catalytic methods for the selective synthesis of amines is a longstanding research objective. In this respect, catalytic deoxygenative amide reduction has proven to be promising but challenging, as this approach necessitates selective C–O bond cleavage. Herein, we report the selective hydroboration of primary, secondary, and tertiary amides at room temperature catalyzed by an earth-abundant-metal catalyst, Zr-H, for accessing diverse amines. Various readily reducible functional groups, such as esters, alkynes, and alkenes, were well tolerated. Furthermore, the methodology was extended to the synthesis of bio- and drug-derived amines. Detailed mechanistic studies revealed a reaction pathway entailing aldehyde and amido complex formation via an unusual C–N bond cleavage-reformation process, followed by C–O bond cleavage.
Synthesis of oxalamides by acceptorless dehydrogenative coupling of ethylene glycol and amines and the reverse hydrogenation catalyzed by ruthenium
Ben-David, Yehoshoa,Diskin-Posner, Yael,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
, p. 7188 - 7193 (2020/07/23)
A sustainable, new synthesis of oxalamides, by acceptorless dehydrogenative coupling of ethylene glycol with amines, generating H2, homogeneously catalyzed by a ruthenium pincer complex, is presented. The reverse hydrogenation reaction is also accomplished using the same catalyst. A plausible reaction mechanism is proposed based on stoichiometric reactions, NMR studies, X-ray crystallography as well as observation of plausible intermediates.
