75-64-9Relevant articles and documents
Factors Controlling Amination of 2-Methylpropene over Proton-exchanged Zeolite Catalysts
Mizuno, Noritaka,Tabata, Masahiro,Uematsu, Takeshi,Iwamoto, Masakuzu
, p. 3513 - 3514 (1993)
The number and strength of Broensted acid sites are factors controlling the amination of 2-methylpropene over proton-exchanged zeolites.Owing to the appropriate possession of the above two factors, proton-exchanged ZSM-5 zeolite with a silica:alumina ratio of 81 was the most active, among the catalysts tested, for the amination.
Reactions of bromoacetylene with primary amine on a butterfly-type tetrairon core to give isonitrile and methyne through oxidation and deprotonation
Okazaki, Masaaki,Tsuchimoto, Takahiro,Nakazawa, Yuki,Takano, Masato,Ozawa, Fumiyuki
, p. 3487 - 3489 (2011)
Reaction of [(η5-C5H4Me) 4Fe4(HCCH)(HCC-Br)](PF6) with tBuNH2 forms [(?5-C5H 4Me)4Fe4(HCCH)(HCC-NHtBu)](PF 6), of which one electron oxidation leads to carbon-carbon bond cleavage to give [(η5-C5H4Me) 4Fe4(HCCH)(μ3-CH)(μ3-CNH tBu)](PF6)2, and further treatment with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) affords [(η5-C 5H4Me)4Fe4(HCCH)(μ3- CH)(μ3-η1-CNtBu)](PF6). Thus, the HCCBr group is converted to tBuNC and CH groups on the redox-responsive tetrairon core.
A shaped binderless ZSM-11 zeolite catalyst for direct amination of isobutene to tert-butylamine
Zhang, Wanshuo,Gao, Shangyao,Xie, Sujuan,Liu, Hui,Zhu, Xiangxue,Shang, Yongchen,Liu, Shenglin,Xu, Longya,Zhang, Ye
, p. 168 - 175 (2017)
A shaped binderless and two binder-containing ZSM-11 zeolite catalysts were prepared and characterized by powder X-ray diffraction, N2adsorption-desorption, and pyridine adsorption-infrared measurements. The binderless catalyst was synthesized using a dry-gel conversion technique, in which 1,6-hexanediamine and tetrabutylammonium bromide were used as structure-directing agents and no other alkaline materials were added. The catalytic performance of the zeolites in the direct amination of isobutene to tert-butylamine was evaluated in a fixed-bed reactor. By virtue of its high crystallinity as well as its good mechanical strength, the shaped binderless ZSM-11 catalyst showed a higher rate of formation of tert-butylamine than did the binder-containing catalysts.
Amination of 2-Methylpropene over Proton-Exchanged ZSM-5 Zeolite Catalysts
Mizuno, Noritaka,Tabata, Masahiro,Uematsu, Takeshi,Iwamoto, Masakazu
, p. 249 - 256 (1994)
The reaction between 2-methylpropene and ammonia over various zeolite catalysts having a wide range of silica/alumina ratios from 5.6 to 1340, and over solid acid catalysts (CsxH3-xPW12O40 (x = 0.15, 0.5), SiO2-Al2O3, and SiO2-TiO2) and the solid base MgO was investigated.The significant decrease of activity following substitution of Na+ for H+ in H-MFI-40 or by preadsorption of diisopropylamine showed that amination is catalyzed by the acid sites.A similar change in the catalytic activity of H-MFI-40 with the number of Broensted acid sites at elevated temperatures, as well as the appearance of activities of CsxH3-xPW12O40 (x = 2.5, 2.85), which has only Broensted acid sites, indicated amination on the Broensted acid site.The dependence of conversion into t-butylamine, the number of Broensted acid sites, and the turnover frequencies on the SiO2/Al2O3 ratio suggested that the number and strength of the Broensted acid sites are the factors controlling the title reaction.Due to the above two factors having the proper values, proton-exchanged ZSM-5 zeolite with a silica/alumina ratio of 81 was the most active for amination among the catalysts tested.
Pd nanoparticles prepared by grafting of Pd complexes on phenol-functionalized carbon supports for liquid phase catalytic applications
Hermans, Sophie,Diverchy, Chantal,Dubois, Vincent,Devillers, Michel
, p. 263 - 271 (2014)
An activated carbon was functionalized by oxidation with HNO3 or H2O2 to increase the number of acidic groups on its surface. A sample of HNO3-oxidized carbon was treated thermally to remove unstable functions. Detailed characterization by a combination of techniques revealed that this stabilization procedure allowed selecting weaker acid sites of phenolic type. H2O2 functionalization gave also mainly surface phenols but in lower amounts. Palladium grafting was carried out in water at room temperature by ligand exchange between a carboxylate complex and the surface oxygenated groups. Activation was carried out thermally and the samples grafted on the most oxidized supports proved more difficult to reduce. The catalytic activity of the obtained Pd/C catalysts was evaluated in the reduction of 2-methyl-2-nitropropane (MNP) into t-butylamine (TBA). The most active materials were those prepared on H2O2-modified carbon and on the stabilized support. In the latter case, the superior activity was explained by the robustness of the grafting anchors which could not decompose during thermal activation together with the active role of weak acidic groups in the catalytic reaction itself.
Organic promoter-driven fast synthesis of zeolite beta and its acceleration mechanism
Zhao, Dongpu,Chu, Weifeng,Wang, Yanan,Zhu, Xiangxue,Li, Xiujie,Xie, Sujuan,An, Jie,Xin, Wenjie,Liu, Shenglin,Xu, Longya
, p. 24614 - 24624 (2018)
Zeolite beta, an important catalytic material widely applied in the petrochemical field, is typically prepared under hydrothermal conditions. However, it usually suffers from the drawback of relatively long crystallization time. Herein, we show that the crystallization rate of zeolite beta can be accelerated by a factor of as much as about nine via the addition of the low-toxic and cost-effective pentacyclic lactam N-methyl-2-pyrrolidone (NMP) as a 'promoter'. Using characterization techniques, we demonstrate that the pentacyclic lactam induces the fast formation of secondary building units (SBUs) and enhances the formation rate of the activated TEA+ species responsible for the nucleation of beta crystals. More importantly, the as-synthesized beta exhibited high product yield (above 85 wt%) and good performance in the direct amination of isobutene (i-C4H8) to tert-butylamine reaction.
C?H Bond Activation by an Imido Cobalt(III) and the Resulting Amido Cobalt(II) Complex
Kraus, Florian,Pietzonka, Clemens,Reckziegel, Alexander,Werncke, C. Gunnar
, p. 8527 - 8531 (2020)
The 3d-metal mediated nitrene transfer is under intense scrutiny due to its potential as an atom economic and ecologically benign way for the directed amination of (un)functionalised C?H bonds. Here we present the isolation and characterisation of a rare, trigonal imido cobalt(III) complex, which bears a rather long cobalt–imido bond. It can cleanly cleave strong C?H bonds with a bond dissociation energy of up to 92 kcal mol?1 in an intermolecular fashion, unprecedented for imido cobalt complexes. This resulted in the amido cobalt(II) complex [Co(hmds)2(NHtBu)]?. Kinetic studies on this reaction revealed an H atom transfer mechanism. Remarkably, the cobalt(II) amide itself is capable of mediating H atom abstraction or stepwise proton/electron transfer depending on the substrate. A cobalt-mediated catalytic application for substrate dehydrogenation using an organo azide is presented.
A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics
García-Domínguez, Andrés,Gonzalez, Jorge A.,Leach, Andrew G.,Lloyd-Jones, Guy C.,Nichol, Gary S.,Taylor, Nicholas P.
supporting information, (2022/01/04)
The kinetics of quinuclidine displacement of BH3 from a wide range of Lewis base borane adducts have been measured. Parameterization of these rates has enabled the development of a nucleofugality scale (NFB), shown to quantify and predict the leaving group ability of a range of other Lewis bases. Additivity observed across a number of series R′3-nRnX (X = P, N; R′ = aryl, alkyl) has allowed the formulation of related substituent parameters (nfPB, nfAB), providing a means of calculating NFB values for a range of Lewis bases that extends far beyond those experimentally derived. The utility of the nucleofugality parameter is explored by the correlation of the substituent parameter nfPB with the hydrolyses rates of a series of alkyl and aryl MIDA boronates under neutral conditions. This has allowed the identification of MIDA boronates with heteroatoms proximal to the reacting center, showing unusual kinetic lability or stability to hydrolysis.
PROCESS FOR PREPARATION OF TERT-BUTYLAMINE AND PROPIONIC ACID SALTS FROM N-TERTIARY BUTYL ACRYLAMIDE
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Page/Page column 15; 16;, (2021/11/13)
Disclosed is a process (100) for conversion of N-tertiary butyl acrylamide to tert-butylamine and salts of propionic acid. The process comprises of first selectively reducing the vinylic double bond in N-tertiary butyl acrylamide by catalytic hydrogenation of an alcoholic solution of N-tertiary butyl acrylamide to provide N-tertiary buyl propanamide; recovering the hydrogenation catalyst by filtering the solution and treating the solution with an alkali to produce N-tertiary butylamine and corresponding alkali salt of propionic acid. The process converts of N-tertiary butyl acrylamide into value added products at milder reaction conditions, without producing any hazardous byproducts and effluents.
Diverse Oxidative C(sp2)-N Bond Cleavages of Aromatic Fused Imidazoles for Synthesis of α-Ketoamides and N-(pyridin-2-yl)arylamides
Xu, Fangzhou,Wang, Yanyan,Xun, Xiwei,Huang, Yun,Jin, Zhichao,Song, Baoan,Wu, Jian
, p. 8411 - 8422 (2019/05/17)
An efficient and chemoselective C(sp2)-N bond cleavage of aromatic imidazo[1,2-a]pyridine molecules is developed. A broad scope of amide compounds such as α-ketoamides and N-(pyridin-2-yl)arylamides are afforded as the final products in up to quantitative yields. Diverse C-N bond cleavages are controlled by the oxidative species used in this transformation, with various amide products afforded in a chemoselective fashion. A preliminary study indicated that some α-ketoamides exhibit anti-Tobacco Mosaic Virus activity for potential use in plant protection.
