Knoevenagel Condensation of Aldehydes with Meldrum's Acid in Ionic Liquids

The Knoevenagel condensation of Meldrum's acid with aromatic aldehydes proceeded efficiently in the recyclable ionic liquid [bmim]BF₄ at room temperature in the presence of catalytic amounts of piperidine.     

Baeyer-Villiger Oxidation of Cyclic Ketones Catalyzed by Amino Acid Ionic Liquids

A series of amino-acid-based ionic liquids was synthesized via one-step protonation of the corresponding L-amino acid by utilizing an array of proton sources. The catalytic activity of the amino-acid-based ionic liquids for the Baeyer-Villiger oxidation of cyclic ketones was investigated using cyclopentanone as a model cycloketone. The proline-based ionic liquid [ProH]CF₃SO₃ was shown to exhibit the best catalytic activity. The reaction condition was optimized to give the following reagent ratio of n(cyclopentanone):n(catalyst):n(H₂O₂)=1:0.06:4, 60℃ and 6 h. Under the optimum conditions, the conversion of cyclopentanone was 96.57% and the selectivity for δ-valerolactone was 73.01%. The catalytic activity was shown to be constant after 4 cycles. A simple treatment was allowed for the recover and the reuse of [ProH]CF₃SO₃. The successful utilization of [ProH]CF₃SO₃ to catalyze a host of cyclic ketones via Baeyer-Villiger oxidation clearly demonstrated the capacity of [ProH]CF₃SO₃ to tolerate variation in the substrate.     

离子液体在Wacker反应中的应用

在60℃及2 MPa条件下,以PdCl2-CuCl2为催化剂,分别在无溶剂、酸性水溶液、1-丁基-3-甲基咪唑六氟磷酸盐(bmimPF6)离子液体为溶剂研究了分子氧氧化1-庚烯生成2-庚酮的Wacker反应。结果表明,在无溶剂、酸性水溶液、bmimPF6溶剂中,均可以得到目标产物2-庚酮,反应6 h后转化率均可达90%以上。在离子液体bmimPF6中,2-庚酮的选择性高于无溶剂和酸性水溶液中的结果。分别在酸性水溶液、bmimPF6溶剂中进行催化剂重复使用实验,研究不同溶剂中催化剂的稳定性。结果显示,在离子液体bmimPF6中催化剂的活性更加稳定,表明可以用离子液体取代传统的有毒、易挥发溶剂进行Wacker反应。     

高活性离子液体催化棉籽油酯交换制备生物柴油

 制备了五种对水稳定性好、带-SO3H 官能团的Bronsted酸离子液体,并用它们催化棉籽油酯交换反应制备生物柴油. 结果表明,磺酸类Bronsted酸离子液体具有很好的催化活性,其催化活性与阳离子中的含氮官能团和碳链长度有关,吡啶丁烷磺酸硫酸氢盐离子液体的催化活性最好,其活性接近于浓硫酸催化剂. 离子液体容易同产物分离,具有很好的稳定性,可以循环使用,对环境友好,是制备生物柴油的较理想催化剂.     

离子液体支载的催化剂在不对称合成反应中循环使用的研究进展

综述了离子液体在不对称催化反应中催化剂循环使用的成功应用及最新进展, 这些反应包括不对称催化氢化反应、不对称环丙烷化反应、不对称环氧化反应、不对称二羟基化反应以及不对称氟化反应.     

Efficient Esterification of Ferrocenecarboxylic Acid in Ionic Liquids

An efficient esterification of ferrocenecarboxylic acid with substituted phenols has been achieved using DCC / DMAP protocol in ionic liquids. The corresponding esters are produced in high yields.     

Development of Ionic Liquids as Green Reaction Media and Catalysts

A brief review of the work carried out at Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences for development of ionic liquid as green reaction media and catalysts is presented. This includes the processes of ionic liquid to be used as catalyst, reaction media, development of functional ionic liquid and methods for synthesis of immobilized ionic liquid. In the end, some prospects for development of ionic liquid are also addressed.     

氯铝酸室温离子液体介质中Blanc氯甲基化反应的研究

在卤化1－烷基吡啶，1－甲基－3－烷基咪唑季胺盐和盐酸三甲胺与无水 AlCl3构成的氯铝酸室温离子液体反应介质中，尝试了苯及其衍生物和氯甲醚的 Blanc氯甲基化反应。结果表明底物的不同对反应有较大影响，苯与氯甲醚反应主 要生成氯甲基化产物，而烷基苯与氯甲醚反应则主要生成二苯基甲烷衍生物。反应 具有适中至高的转化率和选择性，依据底物的不同，反应结束后可以和离子液体系 分层，便于产物分离。氯铝酸离子液体具有一定的重复使用性。     

室温离子液体作为微波吸收剂用于促进Knoevenagel反应

采用催化量的室温离子液体正丁基吡啶硝酸盐 ( [BPy]NO3 ) ,1 正丁基 3 甲基咪唑四氟硼酸盐 ( [bmim]BF4)和1 正丁基 3 甲基咪唑六氟磷酸盐 ( [bmim]PF6)作为微波吸收剂 (敏化剂 ) ,在微波辐射下能顺利地促使一系列芳醛与活泼亚甲基化合物进行Knoevenagel缩合反应 ,以中等到良好产率生成相应E 式烯烃 .     

Synthesis of Dehydroabietic Acid (2-Acryloyloxy) Ethyl Ester in Ionic Liquids

A simple ionic liquid methodology for the synthesis of a novel derivative of dehydroabietic acid is described. 1-Butyl-3-methylimidazolium tetrafluoroborate [bmim]BF₄, a typical ionic liquid, was used as an efficient and environmentally benign solvent in the synthesis of dehydroabietic acid (2-acryloloxy) ethyl ester by O-acylation reaction of dehydroabietic acid chloride with 2-hydroxyethyl acrylate. This new method showed the advantages of mild reaction conditions, short reaction times, good yields, and recyclable solvent.     

Photochemical Schiemann Reaction in Ionic Liquids

Photochemical Schiemann reactions of imidazole derivatives 1 and 4 were carried out in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid [bmim][BF₄] as solvent. The effects of temperature, co-solvent and wavelength on the rate of the reaction and product yield were examined. The use of ionic liquid increases the yield of the photochemical fluorodediazoniation reaction of 2 at 0 °C. Careful temperature control is necessary to minimize the photodecomposition of the ionic liquid in order to increase the yield of product.     

Facile Synthesis of Benzotriazole Derivatives Using Nanoparticles of Organosilane-Based Nitrite Ionic Liquid Immobilized on Silica and Two Room-Temperature Nitrite Ionic Liquids

Nanoparticles of organosilane-based nitrite ionic liquid immobilized on silica, 1-butyl-3-methylimidazolium nitrite, and 1-(3-trimethoxysilylpropyl)-3-methylimidazolium nitrite were used as effective reagents for the preparation of benzotriazole derivatives from 1,2-diaminobenzenes at room temperature under mild solvent-free conditions. These ionic liquids play as nitrosonium sources in this procedure.1,2-Diaminobenzene derivatives have been treated with ionic liquids to give the related diaminobenzenes in very good to excellent yields in short reaction times.

Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the full experimental and spectral details.     

Finkelstein Reaction in Functionalized Crown-ether Ionic Liquids

Recent years, crown ethers have been used in many fields, including phase transfer catalysis, chromatography stationary phase, ionselective electrode, and concentration of metal ions, etc1.. However, the toxicity of free crown ethers makes them unsuitable for industrial use2. Introduction of a crown ether as a functional group to functionalized ionic liquids has been reported3. These functionalized ionic liquids will combine the excellent properties of crown ether and ionic liquids without los…     

含有两个质子酸性位的功能化离子液体的合成

首次合成了含有羧酸基团和HSO4-(或H2PO4-)阴离子的具有两个质子酸性位的功能化离子液体,其结构经TG,1H NMR,13C NMR,IR和元素分析表征。     

Br(o)nsted酸性离子液体催化异丁醛和叔丁醇缩合反应

考察了Br(o)nsted酸性离子液体同时作为溶剂和催化剂催化异丁醛和叔丁醇缩合制备 2,5-二甲基-2,4-己二烯的反应性能.结果表明,Br(o)nsted酸性离子液体具有良好的催化性能,反应后反应产物与离子液体自动分层易分离,离子液体经过真空干燥处理后可以作为溶剂和催化剂循环使用.调变离子液体中的阳离子或阴离子的结构对催化性能有较大的影响.     

Solvent Role of Ionic Liquids in Fundamental Chemical Reaction Dynamics Analyzed by Time-Resolved Spectroscopy

Ionic liquids (ILs), which are used as solvents for chemical reactions, are different from conventional organic solvents owing to their designability. Physicochemical parameters of the ILs, such as polarity and viscosity, that affect chemical equilibria and reaction kinetics can be tuned by changing the combination of anions and cations or by varying the lengths of the alkyl chains present in the cations. We were interested in knowing how these physicochemical parameters affect fundamental chemical reactions in ILs. Therefore, in this personal account, we investigate our recent work on two different photochemical reactions in ILs, namely excited-state intramolecular proton transfer of hydroxyflavone and photodissociation of aminodisulfide, using time-resolved spectroscopic techniques. Interestingly, the roles of the ILs in these chemical reactions are quite different. The effect of the cationic species of the ILs (i. e., the head groups and number of alkyl carbons) on the solvation environment upon photoexcitation and reaction rate are discussed.     

Dy(OTf)3 Catalyzed Reaction of Indole with Aldehydes and Ketones in Ionic Liquids

The use of environmentally benign reaction media is very important in view of today' s environmentally con scious attitude. In connect with this, room temperature ionic liquids that are air and moisture stable have received a good deal of attention in recent years as novel solvent systems for organic synthesis. A number of reactions such as Friedel-Crafts reactions, Diels-Alder cycloadditions, hydrogenations, and Heck reactions have employed ionic liquids as solvents. Among them, the Friedel-Crafts reaction[1] is of great synthetic significance in view of laboratory synthesis and industrial production. Recent studies showed that Friedel-Crafts reaction of indole with carbonyl compounds proceeded readily in aqueous media. [2] However, the aqueous reactions suffer from some common problems,such as tedious work-up, reuse of catalyst and so on.     

离子液体及其在生物催化中的应用

综述了在离子液体中酶及完整细胞的生物催化反应的研究状况, 初步总结了影响离子液体中酶催化反应的因素, 离子液体作为绿色反应介质在生物转化工业中将有广阔的应用前景.     

Brønsted酸性离子液体中电化学合成树枝状聚苯胺

BrФnsted acid ionic liquids were successfully applied to the electrochemical synthesis of polyaniline films on platinum electrode surfaces by using cyclic voltammetry. The scanning electron micrographs showed distinct changes in morphological structures. The films exhibited quite dense packing and good ordering of polymer dendrite as compared with those prepared using conventional hydrochloric acid, indicating that Bronsting acid ionic liquids might be promising alternatives to dual medium-dopants in the synthesis of conducting polymers.     

杂双金属复合物ZABDP催化芳香酮与芳香醛的直接不对称Aldol反应

合成了新型的手性铝/锌杂双金属复合物(R,S,S)-3,3'-二[(N-二苯基脯氨醇)甲基]-2,2'-二羟基-1,1'-联萘酚铝/锌复合物(ZABDP).在催化芳香酮与芳香醛的羟醛缩合(Aldol)反应中,该复合物中的铝作为路易斯酸活化醛,锌的烷氧化物作为Br?nsted碱,使苯乙酮形成活性锌的烯醇化物,2种金属的应用使得芳香醛与芳香酮的直接不对称Aldol反应顺利进行,反应的对映选择性最高达90%,产率最高达99%.