1643-19-2Relevant articles and documents
NMR study of the complex formation between tert-butyl hydroperoxide and tetraalkylammonium bromides
Turovskij, Nikolaj A.,Berestneva, Yulia V.,Raksha, Elena V.,Zubritskij, Mikhail Yu.,Grebenyuk, Serhiy A.
, p. 1443 - 1448 (2014)
The interaction between tert-butyl hydroperoxide and tetraalkylammonium bromides was studied by NMR spectroscopy in acetonitrile-d 3 at 298 K. The complex formation between the hydroperoxide molecule and corresponding quaternary ammonium salt w
Atom transfer radical addition (ATRA) catalyzed by copper complexes with N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) ligand
Kaur, Aman,Gorse, Erin E.,Ribelli, Thomas G.,Jerman, Callista C.,Pintauer, Tomislav
, p. 246 - 252 (2015)
Synthesis, characterization, electrochemical studies and ATRA activity of copper complexes with N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) ligand in the presence of ascorbic acid as a reducing agent were reported. [CuII(TPEN′)Br][Br] (TPEN′ denotes tetracoordinated ligand) catalyst showed a very low activity in ATRA of CBr4 to 1-octene, methyl methacrylate, methyl acrylate and styrene in methanol, which is a typical solvent used for ATRA reactions employing ascorbic acid. On the contrary, the yields and stereoselectivity towards monoadduct formation were dramatically increased in slightly polar but aprotic acetone. Based on molecular structures of isolated [CuII(TPEN)][BPh4] and [CuII(TPEN′)Br][Br] complexes, as well as UV-Vis and cyclic voltammetry studies, an equilibrium was proposed involving inactive [CuII(TPEN)]2+ and ATRP active [CuII(TPEN′)Br]+ cations The halidophilicity of the bromide-based deactivating complex ([CuII(TPEN′)Br][Br]) decreased approximately 750 times upon changing the solvent from acetone (KBr = 3000 ± 230) to methanol (KBr = 4.1 ± 0.1), explaining poor catalytic activity in methanol. In acetone, [CuII(TPEN′)Br][Br] complex was nearly as active in ATRA reactions employing ascorbic acid as previously reported [CuII(TPMA)Br][Br].
Structure and Stability of Quaternary Ammonium Interhalides: Experimental and Quantum-Chemical Study
Simonyan,Kletskii,Chernov'yants,Gol'eva
, p. 575 - 582 (2003)
The electronic structure of a series of ammonium interhalides [R 1R2R3R4N]XI2, where R1 = CH3, C2H5, C3H 7, F, H; R2 = R3 = R4 = CH 3, H; X = Cl, Br, I, was studied by ab initio calculations (RHF/3-21G, RHF/HW, MP2/HW). The thermodynamic stability of these compounds correlates with the strength of the hydrogen bond N-H...X and three-center interhalide bond X-I-I. Calculations confirmed that, in polar solvents, these compounds preferably decompose to [R1R2R3R 4N]+ and XI2- (with subsequent decomposition of the anion), and in nonpolar solvents, to the neutral species [R1R2R3R4N]X and I2. The calculation results were compared to the experimental data obtained by single crystal X-ray diffraction, 1H NMR spectroscopy, and spectrophotometry.
Alternative mechanistic scheme for salt effects on solvolysis reactions of haloalkanes and related compounds in binary DMSO/H2O solvent mixture
Hojo, Masashi,Aoki, Sho
, p. 1023 - 1030,8 (2012)
In 75% (v/v) DMSO/H2O solvent mixture, salt effects on the solvolysis reaction rates of haloalkanes and related compounds (RX) have been examined. In spite of the decreased water activity in the solvent mixture, the log(k/s-1) values of typical Sn1 substrates, such as 1-bromoadamantane, increase with increasing concentration of added metal perchlorates (the order: Li+ + 2+ 2+), which is attributed to the direct chemical interaction between the leaving-group anion and the metal cation in the "modified" solution. Contrastingly, the log(k/s-1) value of an Sn2 substrate decreases with increasing concentration of the metal perchlorates. When nonmetallic salts containing anions (Y- = Cl- or Br -) different from RX (X- = Cl-, Br-, or TsO-) are present, solvolyses of Sn2, such as 1-bromohexane, are subjected to an anion-exchange reaction. By the detailed examination of Δlog(k/s-1)/Δ[Mg(Cl O4) 2] for typical Sn1, Sn1-Sn2 borderline, and Sn2 substrates, we were able to demonstrate a linearity between the Mg(Cl O4)2 effects in the solvolysis rates and the carbocation stabilities expressed by the Gibbs free energy values (ΔG°) of RX in the gas phase. The salt effects on the solvolyses of Sn1 to Sn2 substrates are accounted for without relying on Winstein's reaction scheme or the arbitrary function of ion pairs of two types.
Synthesis method of tetrabutylammonium bromide
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Paragraph 0024-0029; 0030-0035; 0036-0041; 0042-0047; ..., (2021/08/14)
The invention discloses a synthesis method of tetrabutylammonium bromide, which comprises the steps of reflux reaction, crystallization, centrifugation, mother liquor application, centrifugal machine washing and the like, the desolvation operation of dichloroethane is omitted, the evaporation loss of dichloroethane in the desolvation process is avoided, the raw materials are saved, and after the front-section centrifugal mother liquor is supplemented to the formula amount, infinite times of return use can be basically realized, bromobutane and a small amount of tetrabutylammonium bromide contained in the front-section centrifugal mother liquor can be completely put into the production of the next batch, the yield of the product is improved, impurities in the product can be washed away by washing a centrifugal machine with ethyl acetate, the chromaticity of the product is improved, and meanwhile, the post-stage centrifugal mother liquor obtained after centrifugation can be repeatedly used under the condition that the post-stage centrifugal mother liquor is inspected to be qualified, so that raw materials are saved.
Lewis Acidity Scale of Diaryliodonium Ions toward Oxygen, Nitrogen, and Halogen Lewis Bases
Legault, Claude Y.,Mayer, Robert J.,Mayr, Herbert,Ofial, Armin R.
supporting information, (2020/03/13)
Equilibrium constants for the associations of 17 diaryliodonium salts Ar2I+X- with 11 different Lewis bases (halide ions, carboxylates, p-nitrophenolate, amines, and tris(p-anisyl)phosphine) have been investigated by titrations followed by photometric or conductometric methods as well as by isothermal titration calorimetry (ITC) in acetonitrile at 20 °C. The resulting set of equilibrium constants KI covers 6 orders of magnitude and can be expressed by the linear free-energy relationship lg KI = sI LAI + LBI, which characterizes iodonium ions by the Lewis acidity parameter LAI, as well as the iodonium-specific affinities of Lewis bases by the Lewis basicity parameter LBI and the susceptibility sI. Least squares minimization with the definition LAI = 0 for Ph2I+ and sI = 1.00 for the benzoate ion provides Lewis acidities LAI for 17 iodonium ions and Lewis basicities LBI and sI for 10 Lewis bases. The lack of a general correlation between the Lewis basicities LBI (with respect to Ar2I+) and LB (with respect to Ar2CH+) indicates that different factors control the thermodynamics of Lewis adduct formation for iodonium ions and carbenium ions. Analysis of temperature-dependent equilibrium measurements as well as ITC experiments reveal a large entropic contribution to the observed Gibbs reaction energies for the Lewis adduct formations from iodonium ions and Lewis bases originating from solvation effects. The kinetics of the benzoate transfer from the bis(4-dimethylamino)-substituted benzhydryl benzoate Ar2CH-OBz to the phenyl(perfluorophenyl)iodonium ion was found to follow a first-order rate law. The first-order rate constant kobs was not affected by the concentration of Ph(C6F5)I+ indicating that the benzoate release from Ar2CH-OBz proceeds via an unassisted SN1-type mechanism followed by interception of the released benzoate ions by Ph(C6F5)I+ ions.
Synthesis process of tetrabutylammonium bromide
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Paragraph 0061-0072, (2020/12/06)
The invention discloses a synthesis process of tetrabutylammonium bromide. The process is characterized by comprising the following steps: (1) taking dibutylamine and n-butyraldehyde as initial raw materials, taking water as a hydrogen source and butanol as a sacrificial reagent under the action of a modified titanium dioxide photocatalyst, and preparing tributylamine by a photocatalytic continuous micro-channel reactor through a reductive amination mechanism; and (2) after concentrating the obtained tributylamine, making the tributylamine directly dissolved in the solvent and mixed with a certain proportion of n-bromobutane, and then enter the next step continuous micro-channel reactor, such that the target product TBAB can be obtained at the high yield after the reaction is performed for3-5 h at the temperature of 60-90 DEG C. Compared with the kettle type reaction, the continuous reaction temperature is low, the reaction time is short, and the process is safe and efficient.
Application of ionic liquid in synthesis of propylene glycol ether and synthetic method of propylene glycol ether
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Paragraph 0089; 0090, (2018/03/01)
The invention relates to the technical field of chemical engineering catalysis and provides application of ionic liquid in synthesis of propylene glycol ether and a synthetic method of propylene glycol ether. The ionic liquid is methyl carbonate ionic liquid and is taken as a catalyst for catalyzed synthesis of propylene glycol ether. The synthetic method of propylene glycol ether comprises the steps of adding epoxy propane and alcohol into a reactor to be in contact with the catalyst, and heating to 50-200 DEG C in a closed environment, so as to obtain propylene glycol ether, wherein the catalyst is the methyl carbonate ionic liquid. The synthetic method of propylene glycol ether is an environment-friendly synthetic process, has no special requirements on production equipment and is beneficial to industrial production and application, and the process is simple and easy to control.
Method of manufacturing tetrabuthyl ammonium acetate (by machine translation)
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Paragraph 0065, (2017/02/23)
PROBLEM TO BE SOLVED: use raw material, and the solvent through the proper selection of a simple and easy process suitable for the manufacture of solubility of cellulose tet love chill ammonium acetate. SOLUTION: and a starting material by tributylamine, tributylamine in polar aprotic organic solvent and by the reaction of halogenated butyl tetrabuthyl ammonium halide and a process for obtaining, in tetrabuthyl ammonium halide vopo and [...] by the reaction of an alkali metal hydroxide and a process for obtaining, in [...] vopo tetrabuthyl ammonium acetate and acetic acid tetrabuthyl by reaction of the process and to obtain. Selected drawing: fig. 1 (by machine translation)
Effects of charge separation, effective concentration, and aggregate formation on the phase transfer catalyzed alkylation of phenol
Denmark, Scott E.,Weintraub, Robert C.,Gould, Nathan D.
supporting information; experimental part, p. 13415 - 13429 (2012/09/25)
The factors that influence the rate of alkylation of phenol under phase transfer catalysis (PTC) have been investigated in detail. Six linear, symmetrical tetraalkylammonium cations, Me4N+, Et 4N+, (n-Pr)4N+, (n-Bu) 4N+, (n-Hex)4N+, and (n-Oct) 4N+, were examined to compare the effects of cationic radius and lipophilicity on the rate of alkylation. Tetraalkylammonium phenoxide·phenol salts were prepared, and their intrinsic reactivity was determined from initial alkylation rates with n-butyl bromide in homogeneous solution. The catalytic activity of the same tetraalkylammonium phenoxides was determined under PTC conditions (under an extraction mechanism) employing quaternary ammonium bromide catalysts. In homogeneous solution the range in reactivity was small (6.8-fold) for Me4N+ to (n-Oct) 4N+. In contrast, under PTC conditions a larger range in reactivity was observed (663-fold). The effective concentration of the tetraalkylammonium phenoxides in the organic phase was identified as the primary factor influencing catalyst activity. Additionally, titration of active phenoxide in the organic phase confirmed the presence of both phenol and potassium phenoxide aggregates with (n-Bu)4N+, (n-Hex)4N+, and (n-Oct)4N+, each with a unique aggregate stoichiometry. The aggregate stoichiometry did not affect the PTC initial alkylation rates.
