626-67-5Relevant articles and documents
Synthesis and characterization of substituted (aminomethyl)lithium compounds: The structures of [Li2(CH2NPh2)2(THF)3] and [Li4(CH2NC5H10)4(THF)2]
Becke, Frank,Heinemann, Frank W.,Rueffer, Tobias,Wiegeleben, Peter,Boese, Roland,Blaeser, Dieter,Steinborn, Dirk
, p. 205 - 210 (1997)
(Aminomethyl)lithium compounds LiCH2NRR′ · x THF (NRR′ = NMe2 (1a, x = 0), NPhMe (1b, x = 2), NPh2 (1c, x = 1 ... 1,5), NC5H10 (1d, x = 0, NC5H10 = piperidino), and NC7H14 (1e, NC7H14 = 2,6-dimethylpiperidino)) were prepared by the reaction of Bu3SnCH2NRR′ with BuLi. 1a-d were isolated in solid state and characterized by NMR spectroscopy (1H, 13C, 7Li). 1e was obtained in solution and characterized via reaction with MeOH and with benzophenone to generate MeNC7H14 and Ph2C(OH)CH2NC7H14, respectively. Recrystallization of 1c and 1d from n-hexane/THF gives [Li2(CH2NPh2)2(THF)3] (1c′) and [Li4(CH2NC5H10)4(THF)2] (1d′), respectively, whose structures (X-ray) were determined. The dimeric compound 1c′ forms a central planar four-membered Li2C2 ring. One lithium atom is four-coordinated to two methylene carbon atoms (d(Li-C) = 2.246(9), 2.235(9) A) and two oxygen atoms of THF. Unusually, the second lithium exhibits a nearly planar coordination sphere represented by two methylene carbon atoms (d(Li-C) = 2.17(1) and 2.16(1) A) and by the oxygen atom of the disordered THF molecule. 1d′ is a tetrameric species exhibiting a molecular C2 symmetry. The lithium atoms are arranged in a distorted tetrahedron with methylene carbon atoms occupying each face of the tetrahedron.
THE MECHANISM OF THE HETEROGENEOUS CATALYSIS OF α AND γ-CYCLIC SIX-MEMBERED AMINOKETONES
Wysocka, Waleria
, p. 681 - 692 (1985)
On the basis of catalytic deuteration of cyclic α and γ-aminoketones in 1-2N DCl/D2 or H2, in the presence of PtO2, it is assumed that the mechanism of heterogenous catalysis for both classes of compounds is ionic in character, and that the reaction takes place in the electrical double layer at the interface of solid and liquid.As a consequence of the reduction, two deuteriums (or hydrogens if HCl is used) from the reduction medium are introduced into the molecule, the catalyst only facilitating and not participating in the reaction itself.
Electrochemical Reductive N-Methylation with CO2Enabled by a Molecular Catalyst
Rooney, Conor L.,Wu, Yueshen,Tao, Zixu,Wang, Hailiang
supporting information, p. 19983 - 19991 (2021/12/01)
The development of benign methylation reactions utilizing CO2 as a one-carbon building block would enable a more sustainable chemical industry. Electrochemical CO2 reduction has been extensively studied, but its application for reductive methylation reactions remains out of the scope of current electrocatalysis. Here, we report the first electrochemical reductive N-methylation reaction with CO2 and demonstrate its compatibility with amines, hydroxylamines, and hydrazine. Catalyzed by cobalt phthalocyanine molecules supported on carbon nanotubes, the N-methylation reaction proceeds in aqueous media via the chemical condensation of an electrophilic carbon intermediate, proposed to be adsorbed or near-electrode formaldehyde formed from the four-electron reduction of CO2, with nucleophilic nitrogenous reactants and subsequent reduction. By comparing various amines, we discover that the nucleophilicity of the amine reactant is a descriptor for the C-N coupling efficacy. We extend the scope of the reaction to be compatible with cheap and abundant nitro-compounds by developing a cascade reduction process in which CO2 and nitro-compounds are reduced concurrently to yield N-methylamines with high monomethylation selectivity via the overall transfer of 12 electrons and 12 protons.
Germyliumylidene: A Versatile Low Valent Group 14 Catalyst
Sarkar, Debotra,Dutta, Sayan,Weetman, Catherine,Schubert, Emeric,Koley, Debasis,Inoue, Shigeyoshi
supporting information, p. 13072 - 13078 (2021/08/09)
Bis-NHC stabilized germyliumylidenes [RGe(NHC)2]+ are typically Lewis basic (LB) in nature, owing to their lone pair and coordination of two NHCs to the vacant p-orbitals of the germanium center. However, they can also show Lewis acidity (LA) via Ge?CNHC σ* orbital. Utilizing this unique electronic feature, we report the first example of bis-NHC-stabilized germyliumylidene [MesTerGe(NHC)2]Cl (1), (MesTer=2,6-(2,4,6-Me3C6H2)2C6H3; NHC= IMe4=1,3,4,5-tetramethylimidazol-2-ylidene) catalyzed reduction of CO2 with amines and arylsilane, which proceeds via its Lewis basic nature. In contrast, the Lewis acid nature of 1 is utilized in the catalyzed hydroboration and cyanosilylation of carbonyls, thus highlighting the versatile ambiphilic nature of bis-NHC stabilized germyliumylidenes.
Reduction of Amides to Amines with Pinacolborane Catalyzed by Heterogeneous Lanthanum Catalyst La(CH2C6H4NMe2- o)3@SBA-15
Guo, Chenjun,Zhang, Fangcao,Yu, Chong,Luo, Yunjie
supporting information, p. 13122 - 13135 (2021/08/31)
Hydroboration of amides is a useful synthetic strategy to access the corresponding amines. In this contribution, it was found that the supported lanthanum benzyl material La(CH2C6H4NMe2-o)3@SBA-15 was highly active for the hydroboration of primary, secondary, and tertiary amides to amines with pinacolborane. These reactions selectively produced target amines and showed good tolerance for functional groups such as -NO2, -halogen, and -CN, as well as heteroatoms such as S and O. This reduction procedure exhibited the recyclable and reusable property of heterogeneous catalysts and was applicable to gram-scale synthesis. The reaction mechanisms were proposed based on some control experiments and the previous literature. This is the first example of hydroborative reduction of amides to amines mediated by heterogeneous catalysts.
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.
N-Heterocyclic Carbene-Stabilized Germa-acylium Ion: Reactivity and Utility in Catalytic CO2Functionalizations
Sarkar, Debotra,Weetman, Catherine,Dutta, Sayan,Schubert, Emeric,Jandl, Christian,Koley, Debasis,Inoue, Shigeyoshi
supporting information, p. 15403 - 15411 (2020/10/20)
The first acceptor-free heavier germanium analogue of an acylium ion, [RGe(O)(NHC)2]X (R = MesTer = 2,6-(2,4,6-Me3C6H2)2C6H3; NHC = IMe4 = 1,3,4,5-tetramethylimidazol-2-ylidene; X = (Cl or BArF = {(3,5-(CF3)2C6H5)4B}), was isolated by reacting [RGe(NHC)2]X with N2O. Conversion of the germa-acylium ion to the first solely donor-stabilized germanium ester [(NHC)RGe(O)(OSiPh3)] and corresponding heavier analogues ([RGe(S)(NHC)2]X and [RGe(Se)(NHC)2]X) demonstrated its classical acylium-like behavior. The polarized terminal GeO bond in the germa-acylium ion was utilized to activate CO2 and silane, with the former found to be an example of reversible activation of CO2, thus mimicking the behavior of transition metal oxides. Furthermore, its transition-metal-like nature is demonstrated as it was found to be an active catalyst in both CO2 hydrosilylation and reductive N-functionalization of amines using CO2 as the C1 source. Mechanistic studies were undertaken both experimentally and computationally, which revealed that the reaction proceeds via an N-heterocyclic carbene (NHC) siloxygermylene [(NHC)RGe(OSiHPh2)].
Method for synthesizing methyl piperidine through 1- supported metal catalysis (by machine translation)
-
Paragraph 0014-0021, (2020/01/25)
The invention provides a supported metal-catalyzed synthesis method of methyl 1 - piperidine through a supported, metal, wherein the supported metal is, 1,5 - used as catalyst stanediol and methylamine as H a raw material (I) in the following, formula (I). 2 The supported metal, catalyst comprises 230-330 °C, a carrier and 2-4Mpa an active 1-8h, component 1 - wherein. the supported metal catalyst comprises a carrier and an active component: wherein the supported Cu, Ni, Pd/Ru, metal catalyst comprises Cu a Ni carrier and an active component, wherein 3-15%, the Cu total Ni supported amount of 1:1;Pd/Ru the active component (s) 0-1%; and the mass Al ratio (mass ratio) of the active component (s) to the mass of the carrier (s) is in the range. 2 O3 , SiO2 Alternatively, the ZSM - 5. present invention catalyzes the preparation of 1 - a production, 1,5 - route with an 100%,1 - actual application value by a 93%, one-pot process for the catalytic preparation of the conversion rate of methyl.piperidine-pentanediol to methyl piperidine. (by machine translation)
Electroactivated alkylation of amines with alcohols: Via both direct and indirect borrowing hydrogen mechanisms
Appiagyei, Benjamin,Bhatia, Souful,Keeney, Gabriela L.,Dolmetsch, Troy,Jackson, James E.
supporting information, p. 860 - 869 (2020/02/21)
A green, efficient N-alkylation of amines with simple alcohols has been achieved in aqueous solution via an electrochemical version of the so-called "borrowing hydrogen methodology". Catalyzed by Ru on activated carbon cloth (Ru/ACC), the reaction works well with methanol, and with primary and secondary alcohols. Alkylation can be accomplished by either of two different electrocatalytic processes: (1) in an undivided cell, alcohol (present in excess) is oxidized at the Ru/ACC anode; the aldehyde or ketone product condenses with the amine; and the resulting imine is reduced at an ACC cathode, combining with protons released by the oxidation. This process consumes stoichiometric quantities of current. (2) In a membrane-divided cell, the current-activated Ru/ACC cathode effects direct C-H activation of the alcohol; the resulting carbonyl species, either free or still surface-adsorbed, condenses with amine to form imine and is reduced as in (1). These alcohol activation processes can alkylate primary and secondary aliphatic amines, as well as ammonia itself at 25-70 °C and ambient pressure.
N-Methylation and Trideuteromethylation of Amines via Magnesium-Catalyzed Reduction of Cyclic and Linear Carbamates
Magre, Marc,Szewczyk, Marcin,Rueping, Magnus
supporting information, p. 3209 - 3214 (2020/04/10)
A new reduction of carbamates to N-methyl amines is presented. The magnesium-catalyzed reduction reaction allows the conversion of cyclic and linear carbamates, including N-Boc protected amines, into the corresponding N-methyl amines and amino alcohols which are of significant interest due to their presence in many biologically active molecules. Furthermore, the reduction can be extended to the formation of N-trideuteromethyl labeled amines.
