77664-18-7Relevant academic research and scientific papers
Selective C-C bonds formation, N-alkylation and benzo[d]imidazoles synthesis by a recyclable zinc composite
Zhu, Guanxin,Duan, Zheng-Chao,Zhu, Haiyan,Ye, Dongdong,Wang, Dawei
supporting information, p. 266 - 270 (2021/08/06)
Earth abundant metals are much less expensive, promising, valuable metals and could be served as catalysts for the borrowing hydrogen reaction, dehydrogenation and heterocycles synthesis, instead of noble metals. The uniformly dispersed zinc composites were designed, synthesized and carefully characterized by means of XPS, EDS, TEM and XRD. The resulting zinc composite showed good catalytic activity for the N-alkylation of amines with amines, ketones with alcohols in water under base-free conditions, while unsaturated carbonyl compounds could also be synthesized by tuning the reaction conditions. Importantly, it was the first time to realize the synthesis of 2-aryl-1H-benzo[d]imidazole derivatives by using this zinc composite under green conditions. Meanwhile, this zinc catalyst could be easily recovered and reused for at least five times.
Synthesis of NHC-Iridium(III) Complexes Based on N-Iminoimidazolium Ylides and Their Use for the Amine Alkylation by Borrowing Hydrogen Catalysis
Guérin, Vincent,Legault, Claude Y.
supporting information, p. 408 - 417 (2021/02/01)
Anionic NHC ligands recently developed in our group, derived from N-iminoimidazolium ylides, were used to synthesize NHC-iridium(III) complexes. Their catalytic activities were evaluated in the amine alkylation of anilines using borrowing hydrogen catalysis. The high-yielding synthesis of a small library of complexes allowed a rapid screening of the ideal steric bulk of the NHC unit and basicity of the anionic tether for the investigated model reaction. A bulky aromatic N group on the imidazolidene moiety is required to achieve high catalytic activity, and the latter is proportional to the basicity of the anionic group. A selected substrate scope of the reaction was performed, providing fair to excellent yields of the desired alkylated anilines.
Palladium supported on magnesium hydroxyl fluoride: An effective acid catalyst for the hydrogenation of imines and N-heterocycles
Agbossou-Niedercorn, Francine,Corre, Yann,Dongare, Mohan K.,Kemnitz, Erhard,Kokane, Reshma,Michon, Christophe,Umbarkar, Shubhangi B.
supporting information, p. 19572 - 19583 (2021/11/04)
Palladium catalysts supported on acidic fluorinated magnesium hydroxide Pd/MgF2-x(OH)x were prepared through precipitation or impregnation methods. Applications to the hydrogenation of various aldimines and ketimines resulted in good catalytic activities at mild temperatures using one atmosphere of hydrogen. Quinolines, pyridines and other N-heterocycles were successfully hydrogenated at higher temperature and hydrogen pressure using low palladium loadings and without the use of any acid additive. Such reactivity trend confirmed the positive effect of the Br?nsted and Lewis acid sites from the fluorinated magnesium hydroxide support resulting in the effective pre-activation of N-heterocycle substrates and therefore in the good catalytic activity of the palladium nanoparticles during the hydrogenations. As demonstrated in the hydrogenation of imines, the catalyst was recycled up to 10 times without either loss of activity or palladium leaching. This journal is
Nickel Complexes Bearing N,N,O-Tridentate Salicylaldiminato Ligand: Efficient Catalysts for Imines Formation via Dehydrogenative Coupling of Primary Alcohols with Amines
Han, Zhangang,Hao, Zhiqiang,Lin, Jin,Lu, Guo-Liang,Zhang, Junhua,Zhang, Xiaoying
, p. 3843 - 3853 (2021/11/18)
Treatment of salicylaldiminato ligand L1H-L2H (L1H = 2,4-di-tert-butyl-6-((quinolin-8-ylimino)methyl)phenol; L2H = 2,4-di-tert-butyl-6-(((2-(diethylamino)ethyl)imino)methyl)phenol) with Ni(OAc)2·4H2O in refluxing ethanol afforded nickel complexes [(L1)Ni(OAc)] (1) and [(L2)Ni(OAc)] (2), respectively. Reaction of L3H (L3H = (2,4-di-tert-butyl-6-(((2-(pyridin-2-yl)ethyl)imino)methyl)phenol)) with Ni(OAc)2·4H2O in the presence of excess triethylanmine gave the dual ligands coordinated nickel complex [(L2)2Ni] (3). Complexes 1-3 were well characterized by high-resolution mass spectrometry, infrared spectroscopy, elemental analysis, and X-ray diffraction analysis. All the three Ni(II) complexes exhibited efficient activity and good selectivity in the acceptorless dehydrogenative coupling of alcohols and amines to produce imines and diimines. The present protocol provides an atom-economical and sustainable route for the synthesis of various imine derivatives by employing an earth-abundant nickel salt and easily prepared salicylaldiminato ligands.
Method for efficiently realizing N-alkylation reaction by using cyclic iridium catalyst
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Paragraph 0094-0100, (2020/11/10)
The invention discloses a method for efficiently realizing N-alkylation reaction by using a cyclic iridium catalyst, and belongs to the technical field of pharmaceutical and chemical synthesis. The preparation method comprises the following steps of: taking amines and alcohol compounds as raw materials, a cyclic iridium complex as a catalyst and water or an organic solvent as a reaction medium, heating, stirring and reacting for 12-24 hours under the protection of inert gas, cooling to room temperature after the reaction is finished, carrying out reduced pressure distillation and concentrationto obtain a crude product, and carrying out column chromatography purification to obtain a series of amine compounds. The synthesis method of the amine compound is simple to operate, easily availablein raw materials and low in price; the method is high in reaction efficiency, good in N-alkylation selectivity, good in adaptability to various functional groups, wide in substrate universality and environmentally friendly, is carried out at the gram level, shows the potential of industrially synthesizing the N-alkylamine compound, and has wide application prospects in the fields of medicines, organic synthesis and the like.
Pyridine mediated transition-metal-free direct alkylation of anilines using alcohols: via borrowing hydrogen conditions
Pothikumar, Rajagopal,Bhat, Venugopal T,Namitharan, Kayambu
supporting information, p. 13607 - 13610 (2020/11/17)
Herein, we report pyridine and other similar azaaromatics as efficient biomimetic hydrogen shuttles for a transition-metal-free direct N-alkylation of aryl and heteroaryl amines using a variety of benzylic and straight chain alcohols. Mechanistic studies including deuterium labeling and the isolation of dihydro-intermediates of the benzannulated pyridine confirmed the role of pyridine and a borrowing hydrogen process operating in these reactions. In addition, we have extended this methodology for the development of dehydrogenative synthesis of quinolines and indoles, as well as the transfer hydrogenation of ketones. This journal is
Base-mediated cascade amidination/: N -alkylation of amines by alcohols
Hu, Mao-Lin,Jia, Xiaofei,Liang, Zuyu,Lu, Fenghong,Zhang, Chunyan,Zhang, Guoying
supporting information, p. 10489 - 10492 (2020/10/02)
A base-mediated cascade amidination/N-alkylation reaction of amines by alcohols has been developed. For the first time, nitriles have been identified as an efficient and benign water acceptor reagent in N-alkylation. Notably, the procedure tolerates a series of functional groups, such as methoxyl, halo, vinyl and hetero groups, providing a convenient method to construct different substituted diamino compounds, 15N labeled amine and could be scaled up to 1 mol scale offering 138.7 g of the desired product in good yield in one-pot. Mechanistic studies provided strong evidence for the amidination of amines with nitriles facilitated by t-BuOK.
Zinc-Catalyzed N-Alkylation of Aromatic Amines with Alcohols: A Ligand-Free Approach
Sankar, Velayudham,Kathiresan, Murugavel,Sivakumar, Bitragunta,Mannathan, Subramaniyan
supporting information, p. 4409 - 4414 (2020/09/01)
An efficient zinc-catalyzed N-alkylation reaction of aromatic amines was achieved using aliphatic, aromatic, and heteroaromatic alcohols as the alkylating reagent. A variety of aniline derivatives, including heteroaromatic amines, underwent the N-alkylation reaction and furnished the corresponding monoalkylated products in good to excellent yields. The application of the reaction is also further demonstrated by the synthesis of a 2-phenylquinoline derivative from acetophenone and 2-aminobenzyl alcohol. Deuterium labeling experiments show that the reaction proceeds via a borrowing hydrogen process. (Figure presented.).
Thiazoline-Iridium (III) Complexes and Immobilized Nanomaterials as Selective Catalysts in N-Alkylation of Amines with Alcohols
Denizalt?, Serpil,Dayan, Serkan,Günnaz, Salih,?ahin, Ertan
, (2020/10/02)
In this research, a new series of thiazoline-iridium (III) complexes (4–7) derived from cysteine were prepared and fully characterized by conventional methods. The molecular structure of complex 5 was also determined by single-crystal X-ray diffraction. These complexes were evaluated as catalysts for hydrogen-borrowing reactions of amines with alcohols. In particular, complex 5 showed the best activity as catalyst. Various amines have been alkylated with alcohols affording moderate to good yield (33–99%). Moreover, the immobilized nanomaterials (M1,2) were fabricated by sonication process from the best catalyst 5 with the multi-walled carbon nanotubes (MWCNTs) and graphene oxide (GO), respectively, and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) spectroscopy, and inductively coupled plasma-mass spectrometry (ICP-MS). The M1,2 nanomaterials were also tested as catalysts in model catalytic reaction for N-alkylation. The M1 nanomaterial showed significantly higher activity than the M2 nanomaterial. The M1 catalyst was recovered by filtration and reused for four catalytic cycles with high conversion (99%, 97%, 96%, and 86%).
Direct electrochemical reductive amination between aldehydes and amines with a H/D-donor solvent
Chen, Lu,Hong, Huanliang,Hu, Jinhui,Huang, Yubing,Li, Yibiao,Liang, Gen,Pu, Suyun,Zhu, Zhongzhi,Zou, Zirong
supporting information, p. 5832 - 5837 (2020/11/03)
A novel electrochemical synthesis protocol has been achieved for reductive amination between aldehydes and amines in undivided cells at room temperature. Under metal-free and external-reductant-free electrolysis conditions, various important secondary amine products are obtained in moderate-to-high yields. Deuterium-labeling experiments have demonstrated that low-toxicity DMSO acts both as a solvent and a H-donor in the reaction. On this basis, various deuterium-labeled products with good-to-excellent D-incorporation have been synthesized by using DMSO-d6 as a solvent. Furthermore, a molecule with GR-antagonistic activity has been synthesized through further sulfonylation.
