926-63-6Relevant academic research and scientific papers
Organic amine mediated cleavage of Caromatic-Cαbonds in lignin and its platform molecules
Cheng, Xiaomeng,Dong, Minghua,Han, Buxing,Liu, Huizhen,Liu, Shulin,Shen, Xiaojun,Wang, Zhenpeng,Xin, Yu,Yang, Junjuan
, p. 15110 - 15115 (2021/12/04)
The activation and cleavage of C-C bonds remains a critical scientific issue in many organic reactions and is an unmet challenge due to their intrinsic inertness and ubiquity. Meanwhile, it is crucial for the valorization of lignin into high-value chemicals. Here, we proposed a novel strategy to enhance the Caromatic-Cα bond cleavage by pre-functionalization with amine sources, in which an active amine intermediate is first formed through Markovnikov hydroamination to reduce the dissociation energy of the Caromatic-Cα bond which is then cleaved to form target chemicals. More importantly, this strategy provides a method to achieve the maximum utilization of the aromatic nucleus and side chains in lignin or its platform molecules. Phenols and N,N-dimethylethylamine compounds with high yields were produced from herbaceous lignin or the p-coumaric acid monomer in the presence of industrially available dimethylamine (DMA). This journal is
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.
REDUCTIVE PREPARATION OF TERTIARY DIMETHYLAMINES FROM NITRILES
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Paragraph 0055; 0056, (2017/04/04)
This disclosure describes a low temperature process for the preparation of dimethyl amines from nitriles via reductive amination. In some embodiments, the process proceeds under mild conditions with aqeuous dimethylamine and show an unexpected rate acceleration by the inclusion of an acid addition salt of the dimethylamine.
Reductive amination of nitriles using transfer hydrogenation
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Page/Page column 8; 9, (2016/11/09)
This disclosure describes a low temperature process for the preparation of tertiary amines from nitriles and secondary amines via reductive amination using transfer hydrogenation. The process can use a nitrile and a dialkylamine and proceeds under surprisingly mild conditions using a palladium catalyst and the corresponding dialkylammonium formate as the hydrogen donor, and show a pronounced acceleration in the presence of water.
Syntheses, structure solutions, and catalytic performance of two novel layered silicates
Liang, Jie,Su, Jie,Chen, Yanping,Li, Zhaofei,Li, Kuo,Zhang, Hao,Zou, Xiaodong,Liao, Fuhui,Wang, Yingxia,Lin, Jianhua
, p. 15567 - 15575 (2015/09/07)
Two novel layered silicates, PKU-13 and PKU-13a, were hydrothermally synthesized by using trimethylpropylammonium hydroxide as the structure directing agent (SDA). Their structures were solved by using powder X-ray diffraction data in combination with electron diffraction technique and NMR spectroscopy. These two silicates are built from the same r52 layer in different stacking modes: the adjacent r52 layers in PKU-13a have a 0.5b + 0.68c shift compared with those in PKU-13. The difference is due to the SDA cations located between the layers. The SDA cations exist as a monolayer in the structure of PKU-13, and link the adjacent layers by Coulomb actions in combination with strong hydrogen bonds. In PKU-13a, the SDA cations present in the bi-layer expend the distance between layers and destroy the inter-layer hydrogen bonds. PKU-13a can transform to PKU-13 after treatment with acetic acid solution. The co-existence of intra-layer hydrogen bonds in PKU-13 interfere in its condensation to an ordered crystalline microporous framework. Both PKU-13 and PKU-13a exhibit good catalytic activities as base catalysts in the Knoevenagel condensation reaction.
Bis(imino)pyridine cobalt-catalyzed dehydrogenative silylation of alkenes: Scope, mechanism, and origins of selective allylsilane formation
Atienza, Crisita Carmen Hojilla,Diao, Tianning,Weller, Keith J.,Nye, Susan A.,Lewis, Kenrick M.,Delis, Johannes G. P.,Boyer, Julie L.,Roy, Aroop K.,Chirik, Paul J.
supporting information, p. 12108 - 12118 (2014/10/16)
The aryl-substituted bis(imino)pyridine cobalt methyl complex, ( MesPDI)CoCH3 (MesPDI = 2,6-(2,4,6-Me 3C6H2-N=CMe)2C5H 3N), promotes the catalytic dehydrogenative silylation of linear α-olefins to selectively form the corresponding allylsilanes with commercially relevant tertiary silanes such as (Me3SiO) 2MeSiH and (EtO)3SiH. Dehydrogenative silylation of internal olefins such as cis- and trans-4-octene also exclusively produces the allylsilane with the silicon located at the terminus of the hydrocarbon chain, resulting in a highly selective base-metal-catalyzed method for the remote functionalization of C-H bonds with retention of unsaturation. The cobalt-catalyzed reactions also enable inexpensive α-olefins to serve as functional equivalents of the more valuable α, ω-dienes and offer a unique method for the cross-linking of silicone fluids with well-defined carbon spacers. Stoichiometric experiments and deuterium labeling studies support activation of the cobalt alkyl precursor to form a putative cobalt silyl, which undergoes 2,1-insertion of the alkene followed by selective β-hydrogen elimination from the carbon distal from the large tertiary silyl group and accounts for the observed selectivity for allylsilane formation.
Dehydrogenative Silylation and Crosslinking Using Cobalt Catalysts
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Paragraph 0095, (2014/03/24)
Disclosed herein are cobalt complexes containing terdentate pyridine di-imine ligands and their use as efficient and selective dehydrogenative silylation and crosslinking catalysts.
METHOD FOR THE CONTINUOUS PRODUCTION OF AN AMINE USING AN ALUMINUM-COPPER CATALYST
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Page/Page column 9, (2011/08/03)
Process for the continuous preparation of an amine by reaction of a primary or secondary alcohol, aldehyde and/or ketone with hydrogen and a nitrogen compound selected from the group consisting of ammonia, primary and secondary amines at a temperature in the range from 60 to 300° C. in the presence of a catalyst comprising copper oxide and aluminum oxide, wherein the reaction takes place in the gas phase and the catalytically active composition of the catalyst before reduction with hydrogen comprises PS from 20 to 75% by weight of aluminum oxide (Al2O3), from 20 to 75% by weight of oxygen-comprising compounds of copper, calculated as CuO, from 0 to 2% by weight of oxygen-comprising compounds of sodium, calculated as Na2O, and less than 5% by weight of oxygen-comprising compounds of nickel, calculated as NiO, and the shaped catalyst body has a pellet shape having a diameter in the range from 1 to 4 mm and a height in the range from 1 to 4 mm.
Reductive methylation of primary and secondary amines and amino acids by aqueous formaldehyde and zinc
da Silva, Renato A.,Estevam, Idália H.S.,Bieber, Lothar W.
, p. 7680 - 7682 (2008/03/30)
Amines can be methylated when treated with formaldehyde and zinc in aqueous medium. Selective mono- or dimethylation can be achieved by proper choice of pH, stoichiometry and reaction time. This method can also be applied for amino acids.
METHOD FOR THE CONTINUOUS PRODUCTION OF AN AMINE
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Page/Page column 21, (2008/06/13)
The invention relates to a method for the continuous production of an amine by reacting a primary or secondary alcohol, aldehyde and/or ketone with hydrogen and a nitrogen compound, selected from the group including ammonia, primary and secondary amines, at a temperature in the range of from 80 to 350 °C in the presence of a zirconium dioxide-containing catalyst, the catalytically active weight of the catalyst prior to its reduction with hydrogen containing 90 to 99.8 % by weight of zirconium dioxide (ZrO2), 0.1 to 5.0 % by weight of oxygen-containing compounds of palladium and 0.1 to 5.0 % by weight of oxygen-containing compounds of platinum.
