共查询到20条相似文献,搜索用时 15 毫秒
1.
A mild and efficient method has been developed for the preparation of pyrimidinone derivatives from the reaction of aromatic aldehydes with cyclopentanone and urea or thiourea in the presence of N-(4-sulfonic acid) butyl triethyl ammonium hydrogen sulfate ([TEBSA][HSO4]) as the Brønsted acidic ionic liquid and effective catalyst under thermal and solvent-free conditions. Good yields, short reaction times, straightforward workup, reusability of the catalyst, and green conditions are the most obvious advantages of this procedure.
2.
A novel method for the Michael reaction of indoles to α,β‐unsaturated ketones catalyzed by acidic ionic liquid is reported. We obtained the corresponding products in excellent yields in the presence of [hmim]HSO4. Development of this method has resulted in a new protocol for the synthesis of β‐indolylketones. 相似文献
3.
A simple, clean, and environmentally benign three-component process for the synthesis of amidoalkyl naphthols using Brønsted acidic ionic liquids as efficient catalysts in solution and under solvent-free conditions is described. 相似文献
4.
Wei Xing QIAN Feng Yang JU Yong Min ZHANG* Wei Liang BAO Department of Chemistry Zhejiang University 《中国化学快报》2004,15(11)
The urea functional group is of importance in a wide range of biological compounds such as enzyme inhibitors1 and pseudopeptides2. Substituted ureas are widely applied in fine chemical industry, especially pesticides3 and pharmaceuticals4. Many investigations have been made to search for an efficient and practical method to synthesize ureas. The typical procedure for the synthesis of ureas is treating isocyanates with primary or secondary amines in organic solvents5. In the presence of trans… 相似文献
5.
ZHANG Tao YANG Li-Ting LIU Hua-Wei LI Yu-Lin 《有机化学》2003,23(Z1):456-456
Andirolactone 1 as the dextro enantiomer is a sesquiterpenoid with structure of spirocyclic butenolide, isolated from the wood of cedar ( Cedrus libanotica ), which is a needle-leaf tree that grows in southern Turkey and Libanon.The tar, which is obtained from its wood, is used to cure various diseases. [1] 相似文献
6.
Electrochemical Synthesis of Polythiophene in an Ionic Liquid 总被引:6,自引:0,他引:6
Polythiophene(PTh) was prepared by the direct electrochemical synthesis in an ionic liquid ([BMIM]PF6) containing 0.1mol/L thiophene by cyclic voltammetry,constant potential and constant current techniques. It is found that smooth and blue-green PTh films can be obtained at a potential of ca. 1.75V(vs. Ag/AgCl) or a current of ca. 1.5mA cm^-2 in the ionic liquid. 相似文献
7.
8.
Synthesis of Multiester-appended and Multicarboxylic-appended Imidazolium Ionic Liquids 总被引:2,自引:0,他引:2
Wei Guo GENG Xuc Hui LI Le Fu WANG Hong Li DUAN Wei Ping PAN 《中国化学快报》2006,17(2):169-172
Currently ionic liquids (ILs) are attracting considerable interest as eco-friendly solventsfor the replacement of volatile organic solvents in organic synthesis and catalysis1.Low-melting ILs based on imidazolium cations have dominated this area over the … 相似文献
9.
Acylferrocenes 2a–c reacted with ortho-aminoarylaldehydes 1a–e via the Friedländer condensation reaction to afford the corresponding ferrocenylquinolines 3a–o in moderate yields in the presence of sodium ethoxide (30 mmol%) under mild reaction conditions. Under the same reaction conditions, 1,1′-diacetylferrocene 2d and 1,1′-dipropionylferrocene 2e reacted with ortho-aminoaldehydes 1a–e to afford the corresponding 1,1′-bis(substituted quinolin-2-yl)ferrocene derivatives 3p–t. The structures of compounds 3a–t were determined and characterized by infrared, 1H NMR, mass spectrometry, and elemental analysis. The crystal structures of 3e and 3q were determined by x-ray crystallography. 相似文献
10.
We report on the preparation of a well-defined star-shaped tricationic ionic liquid possessing three arms of poly(ethylene glycol) functionalized imidazolium rings. Remarkable solubility was found in most of the organic solvents we used. Thermogravimetric analysis(TGA) exhibited excellent thermal stability and two distinct decomposition temperatures were attributed to two kinds of chemical degradation. Differential scanning calorimetry(DSC) was further employed to investigate the thermal phase transitions, that three different signals(Tg, Tc, and Tm) were shown upon the second heating process. Moreover, CH2Cl2 solution of the ionic liquid expressed an excitation-wavelength dependent fluorescence response, leading to the facile modulation of photoluminescence behavior. This work represents an example of utilizing molecular design to construct novel ionic liquids and endow further potential to be used in the engineering materials. 相似文献
11.
A straightforward and efficient method for preparation of morpholinium bisulfate ([mroH]HSO4) as a novel acidic ionic liquid is reported. The application of this efficient and inexpensive acidic ionic liquid catalyst for tetrahydropyranylation of alcohols under mild and solvent-free conditions at room was investigated. 相似文献
12.
An efficient method for the preparation of 1,3-dioxolanes via the coupling of epoxides with ketones catalyzed by heteropolyacids at ambient temperature has been described. 相似文献
13.
An efficient method has been developed for one-pot three-component coupling reactions of various aldehydes, 1-cyclohexen-2-one, and primary or secondary amines in the presence of a catalytic amount of Yb(OTf)3 under mild conditions to afford the corresponding 2-arylmethyl N-substituted anilines in good yields. In addition, the catalyst was easily recovered and could be reused for at least four cycles without any loss of activity. 相似文献
14.
Dr. Hong Jiang Xiangxiang Zhao Wenqiang Zhang Prof. Yan Liu Dr. Haiyang Li Prof. Yong Cui 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202214748
Chiral imidodiphosphates (IDPs) have emerged as strong Brønsted acid catalysts for many enantioselective processes. However, the dynamic transformation between O,O-syn and O,O-anti conformers typically results in low enantioselectivity. Here we demonstrate that topologies of metal-organic frameworks (MOFs) can be exploited to control IDP conformations and local chiral microenvironments for enantioselective catalysis. Two porous Dy-MOFs with different topologies are obtained from an enantiopure 1,1′-biphenol IDP-based tetracarboxylate ligand. While the ligand adopts a 4- or 3-connected (c) binding mode, all IDPs are rigidified to get only a single O,O-syn conformation and display greatly enhanced Brønsted acidity relative to the free IDP. The MOF with the 4-c IDP that has a relatively less compact shape than the 3-c IDP can be an efficient and recyclable heterogeneous Brønsted acid catalysing the challenging asymmetric O,O-acetalization reaction with up to 96 % enantiomeric excess. 相似文献
15.
The first report of the use of task‐specific ionic liquid as soluble support for the Gewald synthesis of 2‐aminothiophenes is reported in this article. This synthetic method is simple and efficient, and the products are obtained in good to excellent yields with high purities, without the need for chromatographic purification. 相似文献
16.
Xin Ying ZHANG Yan Zhen LI Xue Sen FAN Gui Rong QU Xue Yuan HU Jian Ji WANG 《中国化学快报》2006,17(2):150-152
1, 4-Dihydropyridine (DHP) heterocyclic ring is a common feature of various bioactivecompounds such as vasodilator, bronchodilator and antiatherosclerotic, antitumor, andantidiabetic agents1. Due to their important pharmacological activities, many methods… 相似文献
17.
2-Azido-3,5-dichloropyridine and 2-azido-5-chloro-3-fluoropyridine were given by reaction of sodium azide with 2,3,5-trichloropyridine, 3,5-dichloro-2-fluoropyridine or 5-chloro-2,3-difluoropyridine in ionic liquids. 1,3-Dipolar cycloaddition of 2-azido-3,5-dichloropyridine or 2-azido-5-chloro-3-fluoropyridine to alkynes in ionic liquids afforded the corresponding 1,4,5-trisubstituted [1,2,3]-triazoles in good yields and regioselectivities. 相似文献
18.
A novel ionic liquid, 3‐carboxymethyl‐1‐methylimidazolium bisulfate (CMImHSO4), was synthesized and used as a recyclable catalyst for the Biginelli reaction under solvent‐free conditions. High yields of various substituted 3,4‐dihydropyrimidin‐2(1H)‐ones (or thiones) were obtained. The ionic liquid can be recovered and recycled easily without loss of activity. 相似文献
19.
Davoodnia Abolghasem Heravi Majid M. Rezaei-Daghigh Leila Tavakoli-Hoseini Niloofar 《中国化学》2010,28(3):429-433
A green and improved method for the synthesis of β‐amido ketones through one‐pot multi‐component reaction of an enolizable ketone, aryl aldehyde, acetonitrile or benzonitrile in the presence of trimethylsilyl chloride using 3‐methyl‐1‐(4‐sulfonic acid)butylimidazolium hydrogen sulfate [(CH2)4SO3HMIM][HSO4], a Br?nsted‐acidic ionic liquid, as an effective and recyclable catalyst is described. The present methodology offers several advantages such as simple procedure with an easy work‐up, relatively short reaction time, and good to excellent yields. 相似文献
20.
Cyclodehydration of diethylene glycol using various Brønsted acidic ionic liquids as dual solvent-catalysts has been studied for the first time. Better results were obtained in the presence of 1-butyl-3-methylimidazolium hydrogen sulfate ([PSmim]HSO4) compared with other Brønsted acidic ionic liquids. Effects of the reaction conditions such as reaction temperature, reaction time and molar ratio of ionic liquid to diethylene glycol have been investigated. High diethylene glycol conversion, 97.0 %, and high 1,4-dioxane selectivity, 89.3 %, were obtained in [PSmim]HSO4 under optimum conditions. Hammett method was used to determine the acidity order of these ionic liquids and the results were consistent with the catalytic activities observed in the cyclodehydration reaction. Utilization of Brønsted acidic ionic liquids as dual solvent-catalysts has some advantages, e.g. high conversion of DEG, easy preparation and reuse of ionic liquids, avoiding toxic catalysts and solvents. 相似文献