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.
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.
Powering Artificial Enzymatic Cascades with Electrical Energy
Al-Shameri, Ammar,Apfel, Ulf-Peter,Lauterbach, Lars,Nestl, Bettina M.,Petrich, Marie-Christine,junge Puring, Kai
supporting information, p. 10929 - 10933 (2020/05/04)
We have developed a scalable platform that employs electrolysis for an in vitro synthetic enzymatic cascade in a continuous flow reactor. Both H2 and O2 were produced by electrolysis and transferred through a gas-permeable membrane into the flow system. The membrane enabled the separation of the electrolyte from the biocatalysts in the flow system, where H2 and O2 served as electron mediators for the biocatalysts. We demonstrate the production of methylated N-heterocycles from diamines with up to 99 percent product formation as well as excellent regioselective labeling with stable isotopes. Our platform can be applied for a broad panel of oxidoreductases to exploit electrical energy for the synthesis of fine chemicals.