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.
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.
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.
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.