- Synthesis and Properties of Hydroxyl-Containing Ionic Liquids
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Hydroxyl-containing ionic liquids were synthesized by quaternization of 1,2-dimethyl-1H-imidazole, N-methylpyrrolidine, and pyridine with 2-chloroethanol or 6-chlorohexan-1-ol, followed by exchange of chloride ion for bis(trifluoromethanesulfonyl)azanide, and their properties were studied.
- Krasovskiy,Chernikova,Glukhov,Kapustin,Koroteev,Kustov
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- A new class of ammonium ylid for [2,3]-sigmatropic rearrangement reactions: ene-endo-spiro ylids
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(Chemical Equation Presented) The first examples of sigmatropic rearrangements of ene-endo-spirocyclic, tetrahydropyridine-derived ammonium ylids are reported. Thus, spiro[6.7]-ylids rearrange primarily by a [2,3]-pathway, whereas the analogous [6.6]-ylids rearrange by [1,2]- and [2,3]-mechanisms in roughly equal proportions. This method serves as a rapid entry to the core of a range of alkaloids bearing a pyrrolo[1,2-a]azepine or octahydroindolizidine nucleus.
- Roberts, Edward,Sancon, Julien P.,Sweeney
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- An electrostatic gauche effect in β-fluoro- and β-hydroxy-N- ethylpyridinium cations
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(Figure Presented) Left-leaning molecules: As shown by X-ray crystallography, NMR spectroscopy, and DFT calculations, N-(2-fluoroethyl) pyridinium (see picture; C gray, H white, N blue, F green) and related cations prefer a gauche conformation. In these systems, the gauche effect is attributed to an electrostatic interaction that does not involve hydrogen bonding.
- Gooseman, Natalie E. J.,O'Hagan, David,Peach, Michael J. G.,Slawin, Alexandra M. Z.,Tozer, David J.,Young, Robert J.
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- Exploratory investigations probing a preparatively versatile, pyridinium salt photoelectrocyclization-solvolytic aziridine ring opening sequence
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A novel pyridinium salt photoelectrocyclization-nucleophilic bicyclic aziridine ring opening reaction sequence has been investigated in order to determine its preparative potential. N-Alkylpyridinium perchlorates were found to undergo photoinduced electrocyclization upon irradiation in nucleophilic solvents, such as H2O and MeOH, to efficiently produce 6-alkyl-6-azabicyclo[3.1.0]hex-2-en-4-yl alcohols and ethers. The bicyclic aziridine photoproducts react with a number of different nucleophiles (e.g., H2O, MeOH, AcOH, AcSH) under acid-catalyzed conditions to produce 5-(nucleophile-substituted)-4-(alkylamino)cyclopenten-3-yl alcohols and ethers. The aziridine ring opening processes are both regioselective and stereoselective, yielding trans,trans-trisubstituted cyclopentenes exclusively, apparently as a consequence of the operation of an SN2 mechanism. The effects of C-alkyl substitution on the regiochemistry of the pyridinium cation photocyclization reaction were briefly probed, and a method was developed to produce trans,cis-trisubstituted cyclopentenes by use of this tandem preparative sequence.
- Ling, Rong,Yoshida, Mutsuo,Mariano, Patrick S.
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- DABCO-catalyzed Knoevenagel condensation of aldehydes with ethyl cyanoacetate using hydroxy ionic liquid as a promoter
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N-(2-Hydroxy-ethyl)-pyridinium chloride ([HyEtPy]Cl) was synthesized and explored as a novel promoter for 1,4-diazabicyclo [2.2.2] octane (DABCO)-catalyzed Knoevenagel condensation reactions, which showed better catalytic activity compared to other ionic liquid (IL) that had no hydroxyl group attached to the IL scaffold. The effect of hydrogen bond formation between the hydroxyl group of [HyEtPy]Cl and the carbonyl group of aldehyde played an important role in the Knoevenagel condensation reaction. In the [HyEtPy]Cl-H2O-DABCO composite system, Knoevenagel condensation reactions proceeded smoothly and cleanly, and the corresponding Knoevenagel condensation products were obtained in good to excellent yields in all cases examined. This protocol provides a versatile solvent-catalyst system, which has notable advantages such as being eco-friendly, ease of work-up and convenient reuse of the ionic liquid.
- Meng, Dan,Qiao, Yongsheng,Wang, Xin,Wen, Wei,Zhao, Sanhu
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p. 30180 - 30185
(2018/09/11)
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- A perfluoroalkyl sulfonic acid based on anionic sulfonic acid functionalized ionic liquid and its preparation method
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The invention discloses a sulfonic acid functionalized ionic liquid based on a perfluoro alkyl sulfonic acid radical negative ion and its preparation method, and the structural formula of the ionic liquid is represented by a formula as shown in the specification, wherein m represents 3 or 4, n represents a 1-9 integer, and R is-CH3,-CH2CH3 or-(CH2) 3CH3. The preparation method is as follows: using a substance, which is obtained by reaction of a nitrogen-containing heterocyclic compound with ethylene chlorohydrins, or choline chloride as a precursor; then performing replacement reaction of the precursor and a perfluoro alkyl sulfonate to replace Cl for CF3 (CF2) nSO3 to obtain an intermediate; using sultone and-OH in the intermediate positive ion for performing ring-opening reaction to introduce a sulfonic acid group to obtain the target ionic liquid. The ionic liquid prepared by the method is lower in viscosity, stronger in designable property, and green in synthesis process compared with sulfonic acid functionalized ionic liquids in the prior art, and can be used as a substitute for a traditional liquid acid catalyst, is wider in use range, and has good industrial application prospects.
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Paragraph 0033-0035
(2016/10/17)
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- Cl-H2O: An efficient and versatile solvent system for the DABCO-catalyzed Morita-Baylis-Hillman reaction
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An efficient and versatile solvent-catalyst system, [HyEtPy]Cl-H2O-DABCO, has been developed and used in the Morita-Baylis-Hillman reaction. Under the mild reaction conditions, Morita-Baylis-Hillman proceeds very quickly and efficiently. This protocol has notable advantages such as eco-friendliness, ease of work-up and reuse of ionic liquid conveniently, which could help reduce disposal costs and contribute to the development of a new solvent-catalyst system for use in green and continuous chemical processes.
- Zhao, Sanhu,He, Meiyan,Guo, Zhaonan,Zhou, Na,Wang, Dou,Li, Jinlong,Zhang, Liwei
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p. 32839 - 32845
(2015/04/27)
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- Synthesis, self-aggregation and biological properties of alkylphosphocholine and alkylphosphohomocholine derivatives of cetyltrimethylammonium bromide, cetylpyridinium bromide, benzalkonium bromide (C16) and benzethonium chloride
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A series of alkylphosphocholine and alkylphosphohomocholine derivatives of cetyltrimethylammonium bromide, cetylpyridinium bromide, benzalkonium bromide (C16) and benzethonium chloride have been synthesized. Their physicochemical properties were also investigated. The critical micelle concentration (cmc), the surface tension value at the cmc (γcmc), and the surface area at the surface saturation per head group (Acmc) were determined by means of surface tension measurements. The prepared compounds exhibit significant cytotoxic, antifungal and antiprotozoal activities. Alkylphosphocholines and alkylphosphohomocholines possess higher antifungal activity against Candida albicans in comparison with quaternary ammonium compounds in general. However, quaternary ammonium compounds exhibit significantly higher activity against human tumor cells and pathogenic free-living amoebae Acanthamoeba lugdunensis and Acanthamoeba quina compared to alkylphosphocholines. The relationship between structure, physicochemical properties and biological activity of the tested compounds is discussed.
- Luká?, Milo?,Mrva, Martin,Garajová, Mária,Moj?i?ová, Gabriela,Varinská, Lenka,Moj?i?, Ján,Sabol, Marián,Kubincová, Janka,Haragová, Hana,Ondriska, Franti?ek,Devínsky, Ferdinand
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- New ionic phosphite ligands: Synthesis and application in asymmetric Rh-catalyzed hydrogenation
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A series of chiral ionic phosphite-type ligands bearing pyridinium and imidazolium fragments were prepared. Testing of these ligands in Rh-catalyzed asymmetric hydrogenation of dimethyl itaconate and methyl 2-acetamidoacrylate resulted in 95% ee of the products with 100% conversion of the reactants.
- Lyubimov,Petrovskii,Davankov
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experimental part
p. 528 - 531
(2010/08/21)
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- Ionic liquid phase technology supported the three component synthesis of Hantzsch 1,4-dihydropyridines and Biginelli 3,4-dihydropyrimidin-2(1H)-ones under microwave dielectric heating
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A microwave dielectric heating assisted liquid phase synthesis of 1,4-dihydropyridines, 3,4-dihydropyrimidin-2(1H)-ones, pyridines and polyhydroquinolines using task-specific ionic liquid as a soluble support was described. The efficiency of the ionic liquid phase organic synthesis (IoLiPOS) methodology was demonstrated by using a one-pot three component condensation. The structure of the intermediates in each step was verified routinely by spectroscopic analysis and, after cleavage the target compounds were obtained in good yields and high purities.
- Legeay, Jean-Christophe,Vanden Eynde, Jean Jacques,Bazureau, Jean Pierre
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p. 12386 - 12397
(2007/10/03)
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