927-62-8Relevant articles and documents
Palladium-Assisted Amination of Olefins. A Mechanistic Study
Hegedus, Louis S.,Akermark, Bjorn,Zetterberg, Krister,Olsson, Lars F.
, p. 7122 - 7126 (1984)
The mechanism of the palladium-assisted amination of olefins has been studied by low-temperature NMR and ultraviolat spectroscopy, conductivity measurements, and stoichiometry and exchange studies.The specific sequence of steps followed strongly depends on the temperature of amine.With dimethylamine, the sequence consists of cleavage of the chloride bridge by the amine to give a single olefin-palladium-amine complex (2).This undergoes amination of the olefin and concomitant cyclization to form the β-aminoalkylpalladium complex (3) directly and dimethylammonium hydrochloride.In contrast, with diethylamine, the initially formed olefin-palladium-amine complex undergoes amination to form a discrete zwitterionic complex (6).This reacts slowly with additional added amine to give the chelating β-aminoalkylpalladium complex (7).
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.
Intermittent synthesis method N and N -dimethyl n-butylamine
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Paragraph 0031-0034, (2021/09/26)
The invention relates to N. The invention N-dimethyln-butylamine intermittent synthesis method. Some conversion rates of the main synthetic method of the prior art are relatively low, and some byproducts can be generated, the separation difficulty is increased, the method is economical, N - methylbutylamine is not generated, the separation difficulty is increased, and the production difficulty is large. The method is characterized in that n-butylamine and N-formaldehyde are used as raw materials, and the molar ratio of n-butylamine, n-butylamine and formaldehyde is prepared under the conditions N - and 37 - 40% through nickel catalytic hydrogenation. 60 - 90 °C. 2 - 4 mpa 2 - 1 . 2.6 1. To the invention, a new nickel catalyst is selected. The catalyst cost is reduced, the reaction is prepared by taking n-butylamine and formaldehyde as raw materials, the reaction is simple, the selectivity is good, and the yield is higher.
The selective reductive amination of aliphatic aldehydes and cycloaliphatic ketones with tetragonal zirconium dioxide as the heterogeneous catalyst
Bai, Peng,Li, Jiacong,Tong, Xinli,Wang, Shun,Zhang, Haigang,Zhang, Ming
, (2020/07/17)
A selective reductive amination of aliphatic aldehydes and cycloaliphatic ketones is achieved with tetragonal zirconium dioxide (t-ZrO2) as the catalyst. With N, N-dimethyl formamide (DMF) as the solvent, low-molecular-weight amine source and reductant, a more than 99 percent yield of N, N-dimethylpentan-1-amine or N, N-dimethyl cyclohexanamine was obtained when n-pentanal or cyclohexanone was used as the substrate. Particularly, the crystallographic structures exhibit a significant effect on catalytic performance where the tetragonal crystalline was preferable to monoclinic one during the reductive amination reaction. In addition, the recycling experiments of catalysts indicate that t-ZrO2 still kept a high catalytic activity even after being reused five times. From the result of DFT calculations, it is concluded that the crystalline of zirconium dioxide is closely related to the charge transferring rate between the catalyst and the adsorbed reactant. Finally, based on the experiment phenomena and simulation result, a possible reaction mechanism is proposed for the reductive amination of cyclohexanone.
Ionic liquid/H2O-mediated synthesis of mesoporous organic polymers and their application in methylation of amines
Yu, Xiaoxiao,Yang, Zhenzhen,Zhang, Hongye,Yu, Bo,Zhao, Yanfei,Liiu, Zhenghui,Ji, Guipeng,Liu, Zhimin
supporting information, p. 5962 - 5965 (2017/07/10)
Mesoporous Tr?ger's base-functionalized polymers (Meso-TBPs) were prepared using a sulfonic acid group functionalized ionic liquid/H2O system, with surface areas up to 431 m2 g-1 and pore sizes of 3-15 nm. Ir(ii) coordinated Meso-TBPs exhibited extraordinary catalytic performance in the N-methylation of amines using methanol.
Efficient Cobalt-Catalyzed Methylation of Amines Using Methanol
Liu, Zhenghui,Yang, Zhenzhen,Yu, Xiaoxiao,Zhang, Hongye,Yu, Bo,Zhao, Yanfei,Liu, Zhimin
supporting information, p. 4278 - 4283 (2017/10/23)
The methylation of amines using methanol is a promising route to synthesize N-methylamines, and the development of cheap and efficient catalytic system for this reaction is of great significance. Herein, we reported a cobalt (Co)-based catalytic system, which was in situ formed from commercially available Co precursor and a tetradentate phosphine ligand P(CH2CH2PPh2)3 combined with K3PO4. This catalystic system was very effective for the selective production of dimethylated products from aliphatic amines and monomethylated ones from aromatic amines. The reaction mechanism was further investigated by control and isotope labelling experiments. (Figure presented.).
Copper(II)-Catalyzed Selective Reductive Methylation of Amines with Formic Acid: An Option for Indirect Utilization of CO2
Qiao, Chang,Liu, Xiao-Fang,Liu, Xi,He, Liang-Nian
supporting information, p. 1490 - 1493 (2017/03/23)
A copper-catalyzed protocol for reductive methylation of amines and imine with formic acid as a C1 source and phenylsilane as a reductant is reported for the first time, affording the corresponding methylamines in good to excellent yields under mild conditions. This protocol offers an alternative method for indirect utilization of CO2, as formic acid can be readily obtained from hydrogenation of CO2.
N-Methylation of amines with methanol in a hydrogen free system on a combined Al2O3-mordenite catalyst
Su, Jiahui,Li, Xungang,Chen, Yunbin,Cui, Yuancun,Xu, Jingwei,Qian, Chao,Chen, Xinzhi
, p. 55643 - 55649 (2016/07/06)
N-Methyl amines play a major role in the production of medicines, pesticides, surfactants and dyes. N-Methylation of primary or second amines with methanol is considered to be a green path for the synthesis of N-methyl amines and the catalyst is key. In this article, the combined Al2O3-mordenite catalyst (mass fraction of alumina is 40%) with good activity, selectivity, lifetime and stability was prepared for N-methylation of various amines with methanol in a hydrogen free system in a fixed bed reactor, and characterized by XRD, N2 adsorption and NH3-TPD. Furthermore, the methanol adsorption was investigated by in situ FTIR, and the result indicated that methoxyl species may be the active species for the N-methylation of amines.
Fluoride-Catalyzed Methylation of Amines by Reductive Functionalization of CO2with Hydrosilanes
Liu, Xiao-Fang,Ma, Ran,Qiao, Chang,Cao, Han,He, Liang-Nian
, p. 16489 - 16493 (2016/11/09)
An effective and inexpensive organocatalyst tetrabutylammonium fluoride (TBAF) was developed for the reductive functionalization of CO2with amines to selectively afford formamides or methylamines by employing hydrosilanes. Hydrosilanes with different substituents show discriminatory reducing activity. Thus, the formation of formamides and further reduction products, that is, methylamines could be controlled by elegantly tuning hydrosilane types. Formamides were obtained exclusively under an atmospheric pressure of CO2with triethoxysilane. Using phenylsilane as a reductant, methylamines were attained with up to 99 % yield at 50 °C coupled to a complete deoxygenation of CO2. The crucial intermediate silyl formate in the formylation step was identified and thereby a tentative mechanism involving the fluoride-promoted hydride transfer from the hydrosilane to CO2/formamide was proposed. Striking features of this metal-free protocol are formylation and methylation of amines by reductive functionalization of CO2with hydrosilanes and mild reaction conditions.
Supramolecular Ga4L612- cage photosensitizes 1,3-rearrangement of encapsulated guest via photoinduced electron transfer
Dalton, Derek M.,Ellis, Scott R.,Nichols, Eva M.,Mathies, Richard A.,Dean Toste,Bergman, Robert G.,Raymond, Kenneth N.
supporting information, p. 10128 - 10131 (2015/09/01)
The K12Ga4L6 supramolecular cage is photoactive and enables an unprecedented photoreaction not observed in bulk solution. Ga4L612- cages photosensitize the 1,3-rearrangement of encapsulated cinnamylammonium cation guests from the linear isomer to the higher energy branched isomer when irradiated with UVA light. The rearrangement requires light and guest encapsulation to occur. The Ga4L612- cage-mediated reaction mechanism was investigated by UV/vis absorption, fluorescence, ultrafast transient absorption, and electrochemical experiments. The results support a photoinduced electron transfer mechanism for the 1,3-rearrangement, in which the Ga4L612- cage absorbs photons and transfers an electron to the encapsulated cinnamylammonium ion, which undergoes C-N bond cleavage, followed by back electron transfer to the cage and recombination of the guest fragments to form the higher energy isomer.
