26019-17-0Relevant academic research and scientific papers
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.
Palladium-Catalyzed Reductive Aminocarbonylation of Benzylammonium Triflates with o-Nitrobenzaldehydes for the Synthesis of 3-Arylquinolin-2(1 H)-ones
Liu, Yongzhu,Qi, Xinxin,Wu, Xiao-Feng
, p. 13824 - 13832 (2021/10/12)
A palladium-catalyzed straightforward procedure for the synthesis of 3-arylquinolin-2(1H)-ones has been developed. The synthesis proceeds through a palladium-catalyzed reductive aminocarbonylation reaction of benzylic ammonium triflates with o-nitrobenzaldehydes, and a wide range of 3-arylquinolin-2(1H)-ones was obtained in moderate to good yields with very good functional group compatibility.
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.
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.
Eco-friendly acetylcholine-carboxylate bio-ionic liquids for controllable: N-methylation and N-formylation using ambient CO2 at low temperatures
Zhao, Wenfeng,Chi, Xiaoping,Li, Hu,He, Jian,Long, Jingxuan,Xu, Yufei,Yang, Song
supporting information, p. 567 - 577 (2019/02/14)
Catalytic fixation of CO2 to produce valuable fine chemicals is of great significance to develop a green and sustainable circulation of excessive carbon in the environment. Herein, a series of non-toxic, biodegradable and recyclable acetylcholine-carboxylate bio-ionic liquids with different cations and anions were simply synthesized for producing formamides and methylamines using atmospheric CO2 as a carbon source, and phenylsilane as a hydrogen donor. The selectivity toward products was tuned by altering the reaction temperature under solvent or solvent-free conditions. N-Methylamines (ca. 96% yield) were obtained in acetonitrile at 50 °C, while N-formamides (ca. 99% yield) were attained without a solvent at 30 °C. The established bio-ionic liquid catalytic system found a wide range of applicability in substrates and possessed a high potentiality in scale-up to gram-grade production. The developed catalytic system was fairly stable, which could be easily reused without an apparent loss of reactivity, possibly due to the strong electrostatic interactions between the cation and anion. The combination of experimental and computational results explicitly elucidated the reaction mechanism: PhSiH3 activated by a bio-IL was favorable for the formation of silyl formate from hydrosilylation of CO2, followed by a reaction with an amine to give an N-formamide, while an N-methylamine was formed by further hydrosilylation of the N-formamide.
Selective Monomethylation of Amines with Methanol as the C1 Source
Choi, Geunho,Hong, Soon Hyeok
supporting information, p. 6166 - 6170 (2018/04/30)
The N-monomethyl functionality is a common motif in a variety of synthetic and natural compounds. However, facile access to such compounds remains a fundamental challenge in organic synthesis owing to selectivity issues caused by overmethylation. To address this issue, we have developed a method for the selective, catalytic monomethylation of various structurally and functionally diverse amines, including typically problematic primary aliphatic amines, using methanol as the methylating agent, which is a sustainable chemical feedstock. Kinetic control of the aliphatic amine monomethylation was achieved by using a readily available ruthenium catalyst at an adequate temperature under hydrogen pressure. Various substrates including bio-related molecules and pharmaceuticals were selectively monomethylated, demonstrating the general utility of the developed method.
Direct Synthesis of N,N-Dimethylated and β-Methyl N,N-Dimethylated amines from nitriles using methanol: Experimental and computational studies
Paul, Bhaskar,Shee, Sujan,Panja, Dibyajyoti,Chakrabarti, Kaushik,Kundu, Sabuj
, p. 2890 - 2896 (2018/04/14)
Direct and selective synthesis of N,N-dimethylated amines from nitriles using methanol as C1 building blocks is reported using an air- and moisture-stable ruthenium complex. Following this process, various aromatic as well as aliphatic nitriles were converted to the corresponding N-methylated amines. Interestingly, tandem C-methylation as well as N-methylation was achieved by introducing multiple methyl groups. The practical aspect of this process was revealed by preparative-scale reactions with different nitriles and the synthesis of anti-allergic drug "avil". Several kinetic experiments and detailed DFT calculations were carried out to understand the mechanism of this process.
METHOD FOR PRODUCING N-SUBSTITUTED AMINE COMPOUNDS THROUGH CATALYZED ALKYLATION
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Paragraph 0044, (2014/02/16)
The invention relates to a method for producing a N-substituted amine compound by catalyzed alkylation. The method uses amine and alcohol or two kinds of amines as the reaction materials, employs composite metal oxides catalyst at a reaction temperature of 80-180° C. to catalyze the reaction for 6-36 hours, so as to produce the N-substituted amine compound. The reaction condition of the method of the invention is relatively moderate, using a catalyst made of cheap non-noble metals, which is non-caustic and easy to be separated and reused. The reaction does not need any medium and has relatively high conversion rate and selectivity.
Selective methylation of amines with carbon dioxide and H2
Li, Yuehui,Sorribes, Ivan,Yan, Tao,Junge, Kathrin,Beller, Matthias
supporting information, p. 12156 - 12160 (2013/12/04)
Put a label on it: Carbon dioxide with H2 is shown to be an efficient and selective methylation reagent for aromatic and aliphatic amines (see scheme; acac=acetylacetonate, triphos = 1,1,1- tris(diphenylphosphanylmethyl)ethane). A variety of functionalized amines including 13C-labelled drugs were obtained with good yields and functional-group tolerance. Copyright
Development of a general non-noble metal catalyst for the benign amination of alcohols with amines and ammonia
Cui, Xinjiang,Dai, Xingchao,Deng, Youquan,Shi, Feng
supporting information, p. 3665 - 3675 (2013/03/29)
The N-alkylation of amines or ammonia with alcohols is a valuable route for the synthesis of N-alkyl amines. However, as a potentially clean and economic choice for N-alkyl amine synthesis, non-noble metal catalysts with high activity and good selectivity are rarely reported. Normally, they are severely limited due to low activity and poor generality. Herein, a simple NiCuFeOx catalyst was designed and prepared for the N-alkylation of ammonia or amines with alcohol or primary amines. N-alkyl amines with various structures were successfully synthesized in moderate to excellent yields in the absence of organic ligands and bases. Typically, primary amines could be efficiently transformed into secondary amines and N-heterocyclic compounds, and secondary amines could be N-alkylated to synthesize tertiary amines. Note that primary and secondary amines could be produced through a one-pot reaction of ammonia and alcohols. In addition to excellent catalytic performance, the catalyst itself possesses outstanding superiority, that is, it is air and moisture stable. Moreover, the magnetic property of this catalyst makes it easily separable from the reaction mixture and it could be recovered and reused for several runs without obvious deactivation. Copyright
