共查询到20条相似文献,搜索用时 31 毫秒
1.
Navjeet Kaur 《合成通讯》2018,48(13):1588-1613
The investigation for replacement of organic solvents in organic synthesis is a growing area of interest due to increasing environmental issues. The use of ionic liquid salts as solvents and catalysts in organic reactions has gained extensive interest. Ionic liquids provided a new environmentally benign and improved alternative to traditional methods in modern synthetic chemistry. The aim of present review is to focus on the applications of ionic liquids for the synthesis of O-heterocycles. 相似文献
2.
离子液体溶剂中5-氧代-5,6,7,8-四氢苯并吡喃衍生物的一种温和有效的合成 总被引:1,自引:0,他引:1
A one-pot synthesis of a series of 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran derivatives via three-component coupling reactions of aldehydes, dimedone and malononitrilein room temperature ionic liquids (RTILs) without any catalyst has been reported. In the meantime, the reuse of ionic liquids and the effect of different ionic liquids as solvent on the reaction have also been investigated. 相似文献
3.
The use of ionic liquids as novel solvents for the synthesis of aromatic copoly(ester-amide)s, containing a 9,10-anthraquinone moiety in the main chain, from the polycondensation reaction of terephthaloyl chloride and various ratios of p-phenylenediamine and 1,4-dihydroxyanthraquinone is reported. 1,3-Dialkylimidazolium-based ionic liquids are suitable reaction media for the synthesis of copoly(ester-amide)s. These copolymers exhibit color characteristics and thermal stability. The presence of the amide groups in the backbone of these polymers enhances their thermal stabilities. Inherent viscosities of the polymers obtained in 1,3-dialkylimidazolium bromide range from 0.28 to 0.42 dL/g. 相似文献
4.
Christina Kohlmann Dr. Lasse Greiner Dr. Walter Leitner Prof. Dr. Christian Wandrey Prof. Dr. Stephan Lütz Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(43):11692-11700
Electroenzymatic syntheses combine oxidoreductase‐catalysed reactions with electrochemical reactant supply. The use of ionic liquids as performance additives can contribute to overcoming existing limitations of these syntheses. Here, we report on the influence of different water‐miscible ionic liquids on critical parameters such as conductivity, biocatalyst activity and stability or substrate solubility for three typical electroenzymatic syntheses. In these investigations promising ionic liquids were identified and have been used as additives for batch electrolyses on preparative scale for the three electroenzymatic systems. It was possible to improve the space‐time‐yield for the electrochemical regeneration of NADPH by a factor of three. For an amino acid oxidase catalysed resolution of a methionine racemate with ferrocene‐mediated electrochemical regeneration of the enzyme‐bound cofactor FAD a 50 % increase in space time yield and 140 % increase in catalyst utilisation (TTN) were achieved. Furthermore, for the chloroperoxidase‐catalysed synthesis of (R)‐phenylmethylsulfoxide with electrochemical generation of the required cosubstrate H2O2 the space time yield and the catalyst utilisation were improved by a factor of up to 4.2 depending on the ionic liquids used. 相似文献
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Development in the green synthesis of cyclic carbonate from carbon dioxide using ionic liquids 总被引:3,自引:0,他引:3
Jianmin Sun 《Journal of organometallic chemistry》2005,690(15):3490-3497
This brief review presents the recent development in the synthesis of cyclic carbonate from carbon dioxide (CO2) using ionic liquids as catalyst and/or reaction medium. The synthesis of cyclic carbonate includes three aspects: catalytic reaction of CO2 and epoxide, electrochemical reaction of CO2 and epoxide, and oxidative carboxylation of olefin. Some ionic liquids are suitable catalysts and/or solvents to the CO2 fixation to produce cyclic carbonate. The activity of ionic liquid is greatly enhanced by the addition of Lewis acidic compounds of metal halides or metal complexes that have no or low activity by themselves. Using ionic liquids for the electrochemical synthesis of the cyclic carbonate can avoid harmful organic solvents, supporting electrolytes and catalysts, which are necessary for conventional electrochemical reaction systems. Although the ionic liquid is better for the oxidative carboxylation of olefin than the ordinary catalysts reported previously, this reaction system is at a preliminary stage. Using the ionic liquids, the synthesis process will become greener and simpler because of easy product separation and catalyst recycling and unnecessary use of volatile and harmful organic solvents. 相似文献
7.
Yakov S. Vygodskii Elena I. Lozinskaya Alexandre S. Shaplov 《Macromolecular rapid communications》2002,23(12):676-680
The use of ionic liquids as novel solvents for the synthesis of condensation polymers was investigated. A series of ionic liquids including new ones was synthesized and purified. 1,3‐Dialkylimidazolium‐based ionic liquids seem to be suitable reaction and activating media for the synthesis of high‐molecular‐weight aromatic polyimides and polyamides. Inherent viscosities of the polymers obtained in 1,3‐dialkylimidazolium bromides range from 0.52 to 1.35 dL/g. 相似文献
8.
Ionic liquids are a class of solvents widely studied in the literature for various applications. As a subclass of ionic liquids, redox ionic liquids can endow charge exchange properties (electrons transfer) to these electrolytes for electrochemical energy storage. In this review article, we propose to study this family of ionic liquids and suggest a chronological classification. We introduce five generations of redox ionic liquids with different basic compounds such as polyethylene glycol, ferrocene, different linker lengths, TFSI anion, and biredox ionic liquids. The versatility of the redox ionic liquids synthesis will be discussed as well as the fundamental and applied aspects of their use as electrolytes, which have high charge densities. The impact of the redox ionic liquids on the electrochemical mechanisms will be described. We also present how the redox shuttle effect, detrimental to supercapacitors, can be prevented while it can be used to improve lithium-ion batteries. 相似文献
9.
A method for the synthesis of carboxylic acid derivatives containing one or two —CH2CH
n
(Me)CH
n+1CH2— fragments (n = 0, 1) was developed. The method is based on the alkylation of (di)alkyl malonates, cyanoacetates, and acetoacetates with acyclic prenyl halides in ionic liquids, 1-butyl-3-methylimidazolium hexafluorophosphate and tetrafluoroborate. For the ambident ethyl acetoacetate anion, the reactions with prenyl halides devoid of a double bond in the allylic position relative to the halogen atom carried out in the ionic liquids give mixtures of C- and O-alkylation products, while in the case of allylic prenyl halides, only C-alkylation products are formed. The reactions of ethyl 2-geranylmalonate and 2-geranylacetoacetate with bromocyclohexane and 1-chloro-3-dimethylaminopropane in ionic liquids provided derivatives of pharmacologically active geranylacetic acids. The product yields are higher than those in molecular organic solvents. The ionic liquids were recovered and reused in the alkylation. 相似文献
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Przemysaw Kubisa 《Journal of polymer science. Part A, Polymer chemistry》2005,43(20):4675-4683
Ionic liquids are organic salts that are liquid at ambient temperatures, preferably at room temperature. They are nonvolatile, thermally and chemically stable, highly polar liquids that dissolve many organic, inorganic, and metallo‐organic compounds. Many combinations of organic cations with different counterions are already known, and the properties of ionic liquids may be adjusted by the proper selection of the cation and counterion. In the last decade, there has been increasing interest in using ionic liquids as solvents for chemical reactions. The interest is stimulated not only by their nonvolatility (green solvents) but also by their special properties, which often affect the course of a reaction. In recent years, ionic liquids have also attracted the attention of polymer chemists. Although the research on using ionic liquids in polymer systems is still in its infancy, several interesting possibilities have already emerged. Ionic liquids are used as solvents for polymerization processes, and in several systems they indeed show some advantages. In radical polymerization, the kp/kt ratio (where kp is the rate constant of propagation and kt is the rate constant of termination) is higher than in organic media, and thus better control of the process can be achieved. Ionic liquids, as electrolytes, have also attracted the attention of researchers in the fields of electrochemical polymerization and the synthesis of conducting polymers. Finally, the blending of ionic liquids with polymers may lead to the development of new materials (ionic liquids may act as plasticizers, electrolytes dispersed in polymer matrices, or even porogens). In this article, the new developments in these fields are briefly discussed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4675–4683, 2005 相似文献
12.
AbstractThe viscosity of neat ionic liquids is very important for their application in organic synthesis as a solvent because most of the neat ionic liquids are very viscous, which would result in the less efficient mass transfer of reactants. In the present study, a series of novel dihydro-[1,2,4]triazolo[1,5-a]pyrimidines were prepared using a low viscous and acid-functionalized ionic liquid. Our results showed that new ionic liquid can act as a green solvent and acid catalyst due to low viscosity and acid functionality. The products were simply extracted and the ionic liquid was retrieved several times without reducing its catalytic efficiency. The current application of TMDPS in the one-pot multicomponent reactions as dual solvent-catalyst highlights the importance of low viscous acid-functionalized ionic liquids in organic synthesis, and we hope that further research will be conducted in the future to finding other applications of TMDPS with promising results. 相似文献
13.
离子液体是一种有机盐,在接近室温下呈液状.离子液体是难挥发、极性高的溶剂,它能溶解很多种有机、无机和金属有机化合物.虽然有越来越多的人报道了有关离子液体在有机合成中的应用,但是在聚合过程中的应用却很少.然而在近几年,科学家证明了离子液体在聚合物的合成中的作用很大.在以离子液体为介质的自由基聚合反应中,kp/kt 会增大.尤其是在原子转移自由基聚合中,以离子液体作为溶剂有助于聚合物与残余催化剂的分离.本文主要阐述了原子转移自由基聚合反应的基本原理、特点以及离子液体在原子转移自由基聚合中的应用,并且还介绍了其他研究者的工作和原子转移自由基聚合的发展前景. 相似文献
14.
Dr. Patric Oulevey Dr. Sandra Luber Dr. Birte Varnholt Prof. Dr. Thomas Bürgi 《Angewandte Chemie (International ed. in English)》2016,55(39):11787-11790
Ionic liquids (ILs) are receiving increasing interest for their use in synthetic laboratories and industry. Being composed of charged entities, they show a complex and widely unexplored dynamic behavior. Chiral ionic liquids (CILs) have a high potential as solvents for use in asymmetric synthesis. Chiroptical methods, owing to their sensitivity towards molecular conformation, offer unique possibilities to study the structure of these chiral ionic liquids. Raman optical activity proved particularly useful to study ionic liquids composed of amino acids and the achiral 1‐ethyl‐3‐methylimidazolium counterion. We could substantiate, supported by selected theoretical methods, that the achiral counterion adopts an overall chiral conformation in the presence of chiral amino acid ions. These findings suggest that in the design of chiral ionic liquids for asymmetric synthesis, the structure of the achiral counter ion also has to be carefully considered. 相似文献
15.
Hadi M. Marwani 《Central European Journal of Chemistry》2010,8(4):946-952
In this study, spectroscopic investigation of chiral and achiral room temperature ionic liquids is achieved. New ionic liquids
were prepared via metathesis, accomplished by the reaction of either L-phenylalanine ethyl ester hydrochloride, chlorpromazine hydrochloride
or 1,10-Phenanthroline monohydrate hydrochloride with lithium bis(trifluoromethane) sulfonamide in water. The resulting ionic
liquids were produced in high yield and purity. The results obtained by use of 1H NMR and IR experiments were in very good agreement with the chemical structures of the synthesized ionic liquids. In addition,
the results of thermal gravimetric analysis suggested that these ionic liquids have good thermal stability. UV-Vis and fluorescence
spectroscopy measurements indicated that these ionic liquids are strongly optically absorbent and fluorescent. Lastly, time-based
fluorescence steady-state measurements demonstrated the high photostability of these ionic liquids.
相似文献
16.
For several decades various chemical industries are involved in environment pollution by using hazardous chemicals or excessive use of solvents or catalysts to get maximum amount of desired product. In this case acidic ionic liquids may act as safer substitute of volatile organic solvents/or traditional Brønsted or Lewis acid catalysts with their unique dual task-specific solvent-catalyst properties. Recent surge in the literature review clearly describes the importance, properties and applications of acidic ionic liquids as solvent and efficient reusable catalyst in organic reactions. This review presents an account of some recent reports indicating the synthesis and uses of –SO3H functionalized ionic liquids(SFILs) as catalyst in organic synthesis. 相似文献
17.
Microwave‐enhanced highly efficient protocol for the synthesis of polyfunctional pyridazines beginning from 3,6‐dichloropyridazine in environmentally benign ionic liquids have been developed. The products obtained were 3‐amino‐6‐chloropyridazine, 3,6‐diaminopyridazine, and 3‐chloro‐6‐methoxypyridazine. These derivatives were then be converted to a variety of polyfunctional pyridazine derivatives. The ionic liquids used were 1‐n‐butyl‐3‐methylimidazolium hydroxide/tetrafluoroborate/hexafluorophosphate and 1,3‐di‐n‐butylimidazolium hydroxide. This powerful strategy is less time‐consuming green methodology. The ionic liquid employed may be recovered and recycled. 相似文献
18.
Navjeet Kaur 《合成通讯》2019,49(13):1679-1707
The investigation for replacement of organic solvents in chemical synthesis is a growing area of interest due to increasing environmental issues. The use of ionic liquid salts as solvents and catalysts in organic reactions has gained extensive interest. Ionic liquids provided a new environmentally benign and improved alternative to traditional methods in modern synthetic chemistry. The aim of present review is to focus on the applications of ionic liquids for the synthesis of fused six-membered oxygen heterocycles. 相似文献
19.
Navjeet Kaur 《Phosphorus, sulfur, and silicon and the related elements》2019,194(3):165-185
Some organic solvents are highly toxic, flammable, and even explosive. In particular, high vapor pressures and toxicity of certain volatile organic solvents may cause significant environmental problems. Therefore, alternative solvents or media with tunable and versatile solvation properties for conducting chemical reactions and materials synthesis have been actively sought. Ionic liquids have numerous applications not only as environmentally benign reaction media, but also as catalysts and reagents. Due to the increase of environmental consciousness in chemical research and industry, the challenge for a sustainable environment calls for clean procedures that avoid the use of harmful organic solvents. Due to the special properties of ILs (ionic liquids) such as wide liquid range, good solvating ability, negligible vapor pressure, non-inflammability, non-volatility, environment friendly medium, high thermal stability, good stability in air and moisture, easy recycling and rate promoters etc. they are used in organic synthesis. Therefore, ionic liquids have attracted the attention of chemists and act as catalyst and reaction medium in organic reactions with high activity. Highly efficient methods are explored for the preparation of S-heterocycles with the application of ILs as catalyst and reaction medium. 相似文献
20.
A simple, efficient, and green protocol for synthesis of coumarin-3-carboxylic acids is described via Knoevenagel condensation of Meldrum's acid with ortho-hydroxyaryl aldehydes in [Hmim]Tfa ionic liquid, which was found to give better results than other ionic liquids. Furthermore, ionic liquid is easily reused without any appreciable loss in activity. 相似文献