109-02-4Relevant articles and documents
Synthesis of N-methylmorpholine from morpholine and dimethyl carbonate
Zhu, Maodian,Liu, Shaoying,Deng, Zhiyong,Wang, Gongying
, p. 8427 - 8430 (2013)
The synthesis of N-methylmorpholine from morpholine and dimethyl carbonate was investigated. The effects of reaction variables upon the formation of the compounds were also examined. Under the optimized conditions, higher yield of N-methylmorpholine 83 %
Glycerol as a Building Block for Prochiral Aminoketone, N-Formamide, and N-Methyl Amine Synthesis
Dai, Xingchao,Rabeah, Jabor,Yuan, Hangkong,Brückner, Angelika,Cui, Xinjiang,Shi, Feng
, p. 3133 - 3138 (2016)
Prochiral aminoketones are key intermediates for the synthesis of optically active amino alcohols, and glycerol is one of the main biomass-based alcohols available in industry. In this work, glycerol was catalytically activated and purposefully converted with amines to generate highly valuable prochiral aminoketones, as well as N-formamides and N-methyl amines, over CuNiAlOx catalyst. The catalyst structure can be anticipated as nano-Ni species on or in CuAlOx via the formation of nano- Cu?Ni alloy particles. This concept may present a novel and valuable methodology for glycerol utilization.
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
, p. 15403 - 15411 (2020)
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)].
On the chemical interactions of the biomass processing agents γ-valerolactone (GVL) and: N -methylmorpholine- N -oxide (NMMO)
Bacher, Markus,Hettegger, Hubert,Jusner, Paul,Lê, Huy Quang,Potthast, Antje,Rosenau, Thomas,Sixta, Herbert
, p. 5832 - 5848 (2021)
In new biorefinery processes, NMMO/water is used for the pre-treatment of biomass to increase the efficiency of subsequent digestion processes, while GVL/water is used for organosolv fractionation of biomass. The combination of both methods, GVL digestion after pre-activation by NMMO, appears to be reasonable, but has not been successful. In the present study, we examine the reason for this failure and investigate the chemical processes in the ternary system NMMO/GVL/water and in the quaternary system NMMO/GVL/water/ biomass . The consumption kinetics of NMMO and GVL at different temperatures, water contents and NMMO/GVL ratios were recorded. The respective degradation and reaction products were identified for the first time, by combining nuclear magnetic resonance (NMR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS) techniques and synthesis of authentic compounds for comparison. Decomposition products of NMMO and GVL on their own as well as reaction products of both components together (α-morpholinomethyl-GVL (7), α-methylene-GVL (8), and 4-hydroxyvaleric acid morpholide (13)) were observed among the main degradation products. At temperatures of 150 °C and at a water content a significant extent. While the biomass component cellulose was largely unreactive, lignin was the main culprit that caused degradation reactions in the system. The formation of NMM (5) from NMMO and the resulting ring opening of GVL to 4-hydroxyvaleric acid (3), which is immediately oxidized by NMMO to levulinic acid (4), were the initial reactions that triggered the subsequent, more complex decomposition pathways. The chemical structures of all degradation products were fully analytically confirmed. Due to the instability of the NMMO/GVL system, the combination of NMMO biomass pre-treatment and GVL biomass digestion is prohibited, unless a careful removal of NMMO is carried out beforehand. Besides these practical conclusions with regard to biomass processing in biorefineries, the present study provides hopefully helpful insights into the chemistry of NMMO and GVL and the underlying reaction mechanisms.
Radicals derived from N-methylmorpholine-N-oxide (NMMO): Structure, trapping and recombination reactions
Rosenau,Potthast,Sixta,Kosma
, p. 3073 - 3078 (2002)
The two carbon-centered radicals 4-morpholinomethyl (4) and 4-methylmorpholin-3-yl (5), generated from the primary cation radical intermediate 3 by β-deprotonation, are the major radical species in reaction mixtures of N-methylmorpholine-N-oxide (1) as de
Chiral phosphorus(III) triflates. On the nature of the phosphorus-oxygen interaction
Jones, Victoria A.,Sriprang, Sarin,Thornton-Pett, Mark,Kee, Terence P.
, p. 199 - 218 (1998)
Reaction of chiral phosphorodiamidites with trimethylsilyltriflate affords chiral phophorus(III) triflate species, such as 1-trifluoromethylsulfonato-2,9-(dibenzyl)diaza-1-phospha[4.0.3]bicyclononane 4, which has been examined by a combination of solution and solid state analytical techniques. Arguably the most important feature of this molecule is the nature of the interaction between phosphorus and triflate oxygen atoms. Single crystal X-ray diffraction analysis reveals that the phosphorus atom interacts principally with two oxygen atoms from two different triflate groups in the solid state, implying overall four-coordination at phosphorus. At distances of 2.841 and 2.755 A, these interactions are well within the van der Waals distance for a phosphorus-oxygen [P-O] interaction (ca. 3.35 A) but are nevertheless over 1 A longer than expected for a single [P-O] covalent bond. Investigations in solution via a combination of 31P, 19F, 13C, variable concentration, variable temperature NMR spectroscopy and solution conductivity provide support for a phosphorus-oxygen interaction which is intermediate between 'ionic' (two-coordinate phosphorus) and 'covalent' (three-coordinate phosphorus) and which possesses dynamic character in solution. Indeed, it has proved possible to calculate a relative equilibrium constant between 'ionic' and 'covalent' forms of 4 using empirical NMR data (13C and 19F; CH2Cl2 solvent; 300 K). These calculations return an equilibrium constant of ca. 3 (2.8 using 13C-NMR data and 3.3 using 19F-NMR data) in favour of the ionic form, a result commensurate with those suggested from variable temperature 19F-NMR and solution conductivity studies. Indeed, that the triflate group in 4 is capable of being displaced readily has been demonstrated by reaction with two-electron nitrogen, oxygen and phosphorus donor molecules. We have found 13C{1H}-NMR spectroscopy to be an extremely valuable probe of the ionic character of the triflate group in such systems providing a quantitative measure of the relative strength of interaction (relative basicity Br) between donor molecule and phosphorus atom of 4; the stronger the interaction, the more ionic the character of the triflate group and the lower the value of Br. Indeed, Br values for various ligands correlate well with steric and electronic properties of the latter and 31P-NMR resonances of the adducts themselves. As expected, the relative basicity of a given ligand correlates to the equilibrium constants K for adduct formation, which range from 39 M-1 for the weakest binding ligand studied (1,4-dioxane) to 5.4×104 M-1 for the strongest binding ligand (4-Me2N-NC5H4).
Selective synthesis of formamides, 1,2-bis(N-heterocyclic)ethanes and methylamines from cyclic amines and CO2/H2 catalyzed by an ionic liquid-Pd/C system
Li, Ruipeng,Zhao, Yanfei,Wang, Huan,Xiang, Junfeng,Wu, Yunyan,Yu, Bo,Han, Buxing,Liu, Zhimin
, p. 9822 - 9828 (2019)
The reduction of CO2 with amines and H2 generally produces N-formylated or N-methylated compounds over different catalysts. Herein, we report the selective synthesis of formamides, 1,2-bis(N-heterocyclic)ethanes, and methylamines, which is achieved over an ionic liquid (IL, e.g., 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIm][BF4])-Pd/C catalytic system. By simply varying the reaction temperature, formamides and methylamines can be selectively produced, respectively, in high yields. Interestingly, 1,2-bis(N-heterocyclic)ethanes can also be obtained via the McMurry reaction of the formed formamide coupled with subsequent hydrogenation. It was found that [BMIm][BF4] can react with formamide to form a [BMIm]+-formamide adduct; thus combined with Pd/C it can catalyze McMurry coupling of formamide in the presence of H2 to afford 1,2-bis(N-heterocyclic)ethane. Moreover, Pd/C-[BMIm][BF4] can further catalyze the hydrogenolysis of 1,2-bis(N-heterocyclic)ethane to access methylamine. [BMIm][BF4]-Pd/C was tolerant to a wide substrate scope, giving the corresponding formamides, 1,2-bis(N-heterocyclic)ethanes or methylamines in moderate to high yields. This work develops a new route to produce N-methylamine and opens the way to produce 1,2-bis(N-heterocyclic)ethane from cyclic amine as well.
An Improved Rapid and Mild Deoxygenation of Amine N-oxides
Rajesh
, p. 486 - 491 (2018)
An improved mild and selective method for the deoxygenation of a variety of amine N-oxides has been carried out in the presence of silica gel under mild conditions at room temperature to afford corresponding amines in relatively good yields without purification. The reaction is tolerant of a variety of functional groups such as hydroxyl, ester, acid, carbonyl, and cyano groups, as well as halogens. This method would be of great utility to synthesize various pyridines and amines easily.
Self-Sufficient Formaldehyde-to-Methanol Conversion by Organometallic Formaldehyde Dismutase Mimic
van der Waals, Dominic,Heim, Leo E.,Vallazza, Simona,Gedig, Christian,Deska, Jan,Prechtl, Martin H. G.
, p. 11568 - 11573 (2016)
The catalytic networks of methylotrophic organisms, featuring redox enzymes for the activation of one-carbon moieties, can serve as great inspiration in the development of novel homogeneously catalyzed pathways for the interconversion of C1molecules at ambient conditions. An imidazolium-tagged arene–ruthenium complex was identified as an effective functional mimic of the bacterial formaldehyde dismutase, which provides a new and highly selective route for the conversion of formaldehyde to methanol in absence of any external reducing agents. Moreover, secondary amines are reductively methylated by the organometallic dismutase mimic in a redox self-sufficient manner with formaldehyde acting both as carbon source and reducing agent.
Germyliumylidene: A Versatile Low Valent Group 14 Catalyst
Sarkar, Debotra,Dutta, Sayan,Weetman, Catherine,Schubert, Emeric,Koley, Debasis,Inoue, Shigeyoshi
, p. 13072 - 13078 (2021)
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.
