120-94-5Relevant articles and documents
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Nakajima
, p. 1218 (1961)
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Searles et al.
, p. 4917,4918 (1956)
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Gas-Phase Elimination Kinetics of (Dimethylamino)alkyl Acetates. The Ion-Pair Mechanism through Neighboring Group Participation.
Chuchani, Gabriel,Rotinov, Alexandra,Dominguez, Rosa M.,Gonzalez, Neil
, p. 4157 - 4160 (1984)
The gas-phase elimination kinetics of some amino esters and a keto acetate have been studied in the temperature region of 260.0-411.5 deg C and in the pressure range of 21.5-170.0 torr.These eliminations, in vessels seasoned with allyl bromide, are predominantly unimolecular and homogenous and obey a first order rate law.The rate coefficients for the reactions are expressible by the following Arrhenius equations: for 3-(dimethylamino)-1-propyl acetate (1), log k1 (s-1) = (12.97 +/- 0.20) - (202.1 +/- 2.5) kJ mol-1 (2.303RT)-1; for 4-(dimethylamino)-1-butyl acetate (4), log k1 (s-1) = (11.91 +/- 0.43) - (163.5 +/- 4.8) kJ mol-1 (2.303 RT)-1; for 4-oxo-1-pentyl acetate (7), log k1 (s-1) = (12.77 +/- 0.36) - (202.8 +/- 4.6) kJ mol-1 (2.303RT)-1.The presence of the (CH3)2N group in these acetates appears to provide anchimeric assistance in the elimination; methyl acetate and the corresponding heterocyclic products arise from an intimate ion-pair mechanism.The CH3CO substituent is believed to influence the pyrolysis rate of 5-acetoxy-2-pentanone by a weak steric acceleration.
Poisoning and Reuse of Supported Precious Metal Catalysts in the Hydrogenation of N-Heterocycles Part?I: Ruthenium-Catalysed Hydrogenation of 1-Methylpyrrole
Heged?s, László,Sz?ke-Molnár, Kristóf,Sajó, István E.,Srankó, Dávid Ferenc,Schay, Zoltán
, p. 1939 - 1950 (2018)
Abstract: Poisoning phenomena of heterogeneous, supported precious metal catalysts caused by nitrogen were investigated in the liquid-phase hydrogenation of 1-methylpyrrole (MP) to 1-methylpyrrolidine (MPD) over ruthenium on carbon, in non-acidic medium (methanol), at 10?bar and 25–60?°C. Reusing a spent, unregenerated 5% Ru/C catalyst, it was found that the activity of catalyst and the conversion of model substrate were strongly dependent on the amount of catalyst and the number of recycling, respectively. During the first reuse of this ruthenium catalyst, surprisingly, it showed high activity already at room temperature contrary to the fresh catalyst which worked at only 60?°C. This unexpected catalytic behaviour was studied by XRD and XPS methods which revealed the existence of a fine RuO2 layer on the surface of the catalytic metal in the fresh catalyst. Graphical Abstract: [Figure not available: see fulltext.].
Preparation and GC-MS-Identification of N-Methyl-Δ3-pyrroline
Mahboobi, Siavosh,Fischer, Erich Chr.,Eibler, Ernst,Wiegrebe, Wolfgang
, p. 423 - 424 (1988)
The preparation of N-methyl-Δ3-pyrroline by 1) reduction of N-methyl-pyrrole followed by gc-separation or by 2) condensation of cis-1,4-dichloro-2-butene with methylamine is described.The title compound is identified by GC-MS.
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.
Highly economical and direct amination of sp3carbon using low-cost nickel pincer catalyst
Brandt, Andrew,Rangumagar, Ambar B.,Szwedo, Peter,Wayland, Hunter A.,Parnell, Charlette M.,Munshi, Pradip,Ghosh, Anindya
, p. 1862 - 1874 (2021/01/20)
Developing more efficient routes to achieve C-N bond coupling is of great importance to industries ranging from products in pharmaceuticals and fertilizers to biomedical technologies and next-generation electroactive materials. Over the past decade, improvements in catalyst design have moved synthesis away from expensive metals to newer inexpensive C-N cross-coupling approaches via direct amine alkylation. For the first time, we report the use of an amide-based nickel pincer catalyst (1) for direct alkylation of amines via activation of sp3 C-H bonds. The reaction was accomplished using a 0.2 mol% catalyst and no additional activating agents other than the base. Upon optimization, it was determined that the ideal reaction conditions involved solvent dimethyl sulfoxide at 110 °C for 3 h. The catalyst demonstrated excellent reactivity in the formation of various imines, intramolecularly cyclized amines, and substituted amines with a turnover number (TON) as high as 183. Depending on the base used for the reaction and the starting amines, the catalyst demonstrated high selectivity towards the product formation. The exploration into the mechanism and kinetics of the reaction pathway suggested the C-H activation as the rate-limiting step, with the reaction second-order overall, holding first-order behavior towards the catalyst and toluene substrate.
