646-58-2Relevant academic research and scientific papers
Weakly polar aprotic ionic liquids acting as strong dissociating solvent: A typical ionic liquid effect revealed by accurate measurement of absolute pKa of ylide precursor salts
Mao, Chong,Wang, Zedong,Wang, Zhen,Ji, Pengju,Cheng, Jin-Pei
, p. 5523 - 5526 (2016)
Absolute pKas of selected salts with different counter-anions were measured with high precision in four aprotic ionic liquids (AILs), which enables a detailed examination of solvation effect of ILs on salts. Interestingly, the counter-anions of the ylide precursor salts, protic amine, and phenol salts of this study, though differing dramatically in size and electron dispersion, were found to have no effect on the respective pKas of the substrates. This indicates that the ionic species generated upon acidic dissociation of the salts in weakly polar AILs of low dielectric constant (?: 10-15) are not ion-paired, or in other words, behave like free ions as if in strongly dissociating molecular solvents of high polarity (e.g., DMSO). This suggests that the widely assumed ionpairing phenomenon, an issue of much debate, is not important in the AILs under our experimental conditions, presenting a typical ionic-liquid effect on the solvation of charged species in AILs.
Palladium-Catalyzed Hydride Addition/C-H Bond Activation Cascade: Cycloisomerization of 1,6-Diynes
Rodríguez, José F.,Burton, Katherine I.,Franzoni, Ivan,Petrone, David A.,Scheipers, Ina,Lautens, Mark
supporting information, p. 6915 - 6919 (2018/11/21)
The use of ammonium halide salts as metal hydride precursors in a new Pd-catalyzed cycloisomerization of 1,6-diynes, which affords unexplored silylated 2-azafluorenes, is reported. This cascade process includes the addition of a Pd-hydride species to a π-system, intramolecular carbopalladation, and C(sp2)-H bond activation. A variety of functional groups are tolerated, and the synthetic utility of the resulting products has been demonstrated by a series of derivatizations.
Triethylammonium-based protic ionic liquids with sulfonic acids: Phase behavior and electrochemistry
Shmukler,Gruzdev,Kudryakova,Fadeeva, Yu A.,Kolker,Safonova
, p. 139 - 146 (2018/06/26)
Six triethylammonium-based protic ionic liquids (PILs) and two molten salts were synthesized via a proton transfer reaction from sulfonic acid to triethylamine (TEA). The PILs were characterized by 1H NMR, 13C NMR, 1H/15N NMR and FT-IR spectroscopic methods. The phase behavior of the PILs was studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The temperature dependences of the PILs electrical conductivity, viscosity, and electrochemical stability window (ECW) were studied. The highest electrical conductivity and ECW values are registered in triethylammonium triflate. The thermal and electrochemical characteristics of the salts obtained in this work have been analyzed in comparison with the literature data by the properties of triethylammonium-based salts with sulfonic acids.
Vaporization of protic ionic liquids studied by matrix-isolation fourier transform infrared spectroscopy
Horikawa, Mami,Akai, Nobuyuki,Kawai, Akio,Shibuya, Kazuhiko
, p. 3280 - 3287 (2014/06/09)
Several protic ionic liquids (PILs) with a wide range of pKa differences (ΔpKa) between the parent acid and base molecules were thermally evaporated in vacuum, trapped on a CsI plate by a cryogenic neon matrix-isolation method, and studied by Fourier transform infrared spectroscopy and density functional theory calculations. The parent neutral molecules and proton-transferred cation-anion pair species were identified as chemical components evaporated from the PILs with lower and higher ΔpKa values, respectively. The ΔpKa-dependent vaporization mechanism is discussed in terms of thermodynamic equilibrium between acid-base and anion-cation systems in the liquid phase.
Ionic liquid enhanced alkylation of iso-butane and 1-butene
Cui, Peng,Zhao, Guoying,Ren, Hailing,Huang, Jun,Zhang, Suojiang
, p. 30 - 35 (2013/02/22)
The alkylation of iso-butane with 1-butene was catalyzed by triflic acid (TFOH) coupled with a series of protic ammonium-based ionic liquids (AMILs), and the addition of the AMILs dramatically enhanced the efficiency of TFOH for the alkylation reaction. Up to 85.1% trimethylpentanes (TMP) selectivity and 98 research octane number (RON) were achieved with the optimized TFOH/AMIL catalyst (75 vol.% triflic acid and 25 vol.% triethylammonium hydrogen sulfate), which were much better than that with the commercial H2SO4 catalyst (65% TMP selectivity, 97 RON) and pure triflic acid. The addition of AMILs increased the I/O ratio dissolved in the catalyst system and adjusted the acidity of the TFOH/AMILs catalyst system, which were highly beneficial to the alkylation reaction and resulted in high TMP selectivity and high RON.
Rapid and efficient protic ionic liquid-mediated pinacol rearrangements under microwave irradiation
Henderson, Luke C.,Byrne, Nolene
supporting information; experimental part, p. 813 - 816 (2011/06/20)
Several protic ionic liquids were tested as potential mediators for pinacol rearrangements employing microwave irradiation. Using hydrobenzoin as a model substrate, the optimal conditions were found to be heating at 80°C for 5 min using H2SO4:triethylamine as the ionic liquid. A key feature of this reaction was to keep the microwave power low (20 W) to avoid ionic liquid degradation. Application of these conditions to triphenylethylene glycol gave rearrangement products in high yield and purity, while phenylethylene glycol and styrene oxide gave pinacol products that underwent a cascade aldol condensation. These conditions represent an efficient means by which pinacol rearrangements can be carried out while avoiding the use of strong Bronsted acids, high temperatures and extended reaction times. The Royal Society of Chemistry.
Do all the protic ionic liquids exist as molecular aggregates in the gas phase?
Zhu, Xiao,Wang, Yong,Li, Haoran
experimental part, p. 17445 - 17448 (2012/07/17)
According to an EI-MS study of 1,1,3,3-tetramethylguanidium-based protic ionic liquids (PILs), it has been concluded that not all PILs exist as molecular aggregates in the gas phase. The detection of both ions of m/z 115.0 and m/z 116.0 for the 1,1,3,3-tetramethylguanidinium trifluoromethylsulfonate (TMGS) protic ionic liquid indicates that both the molecular and ionic aggregates co-exist in the gas phase, which is to say that the TMGS may also evaporate via the ionic aggregates just like aprotic ionic liquids. Furthermore, investigation on triethylamine-based and 1-methylimidazole-based PILs confirmed that the gas phase structure of PILs depends on both the acidity and basicity of the corresponding acid and base. This journal is the Owner Societies.
Precursors for CVD Silicon Carbo-nitride Films
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Page/Page column 3, (2009/04/24)
Classes of liquid aminosilanes have been found which allow for the production of silicon-containing films. These aminosilanes, in contrast, to some of the precursors employed heretofore, are liquid at room temperature and pressure allowing for convenient handling. In addition, the invention relates to a process for producing such films. The classes of compounds are generally represented by the formulas: and mixtures thereof, wherein R and R1 in the formulas represent aliphatic groups typically having from 2 to about 10 carbon atoms, e.g., alkyl, cycloalkyl with R and R1 in formula A also being combinable into a cyclic group, and R2 representing a single bond, (CH2)n, a ring, or SiH2.
Boron complexation strategy for use in manipulating 1-acyldipyrromethanes
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Page/Page column 18, (2008/06/13)
A method of making a metal complex comprises combining a 1-monoacyldipyrromethane with a compound of the formula R1R2MX, wherein M is boron, R1 and R2 are each independently organic substituents; and X is an anion leaving group; to produce a metal complex of the formula DMR1R2 wherein DH is a 1-monoacyldipyrromethane. The methods and complexes are useful for the purification and synthesis of dipyrromethanes and porphyrins.
Zur Synthese neuartiger Triflate der 14. Gruppe
Uhlig, W.
, p. 377 - 383 (2007/10/02)
Trifluoromethanesulfonates of silicon, germanium, tin and lead are obtained by cleavage of the corresponding phenyl derivatives with CF3SO3H.Selective cleavage of the tin-carbon bond is observed in the case of silyl- and germylstannanes.Reaction of bis(trifluoromethanesulfonates) with lithiumorganic compounds leads to functional substituted triflate derivatives.
