Co-reporter:Ligang Luo, Chunze Liu, Zhiqiang Hou, Yuanyuan Wang and Liyi Dai
RSC Advances 2014 vol. 4(Issue 56) pp:29527-29533
Publication Date(Web):19 Jun 2014
DOI:10.1039/C4RA04689G
We herein report a mild method for the preparation of dihydrobenzofurans through hydrothermal catalytic tandem Claisen rearrangement–intramolecular hydroaryloxylation of allyl phenyl ethers. This reaction provides a new method for constructing dihydrobenzofurans, a process that is potentially applicable to natural product synthesis. SBA-15, TS-1, HZSM-5 were chosen as catalysts in a hydrothermal reaction medium between 200 and 320 °C. HZSM-5 catalyst showed the highest catalytic activity, and the effects of molar ratio of allyl phenyl ether–water, time, pressure, temperature and catalyst on the Claisen hydroaryloxylation in hydrothermal condition were investigated. The latter two process variables had the greatest influence on the product yields and distribution. A series of allyl phenyl ether derivatives were also treated in hydrothermal condition with HZSM-5 catalyst to offer high yield of corresponding dihydrobenzofurans.
Co-reporter:Li-Cai Zhao, Zhi-Qiang Hou, Chun-Ze Liu, Yuan-Yuan Wang, Li-Yi Dai
Chinese Chemical Letters 2014 Volume 25(Issue 10) pp:1395-1398
Publication Date(Web):October 2014
DOI:10.1016/j.cclet.2014.05.012
Diethyl carbonate has been synthesized via the alcoholysis of ethyl carbamate in supercritical ethanol under catalyst-free conditions. The influences of various parameters such as reaction temperature, reaction time, reaction pressure, ethanol/ethyl molar ratios and reaction loading volume on the yield of DEC were studied systematically. The experimental results indicated that the alcoholysis of ethyl carbamate was greatly improved in supercritical ethanol. The optimal reaction conditions were as follows: a reaction temperature of 573 K, a reaction time of 30 min, a reaction pressure of 13.2 MPa, an ethanol/ethyl carbamate molar ratio of 10 and a reactor loading volume of 285 μL respectively. The optimal yield of DEC was 22.9%.The synthesis of diethyl carbonate from ethyl carbamate was achieved for the first time in supercritical ethanol without any catalyst under the following conditions: a reaction temperature of 573 K, a reaction time of 30 min, a reaction pressure of 13.2 MPa, an ethanol/EC molar ratio of 10, a reactor loading of 285 μL.
Co-reporter:Yuanyuan Wang, Junlong Zhou, Kun Liu and Liyi Dai
RSC Advances 2013 vol. 3(Issue 25) pp:9965-9972
Publication Date(Web):10 Apr 2013
DOI:10.1039/C3RA00133D
Several bi-SO3H-functionalized room temperature ionic liquids were synthesized and their catalytic performances for the synthesis of naphthalene-condensed oxazinone derivatives were studied theoretically, as well as experimentally. Compared with traditional single-SO3H-functionalized ionic liquids, less catalyst and higher yields are the key features of this methodology. Hammett function values and the minimum-energy geometries of bi-SO3H-functionalized ionic liquids were calculated and the results revealed that the acidities and catalytic activities of ionic liquids in the synthesis of naphthalene-condensed oxazinone derivatives were influenced by their structures. There are strong hydrogen bond networks in these bi-SO3H-functionalized ionic liquids. The H–O bond of the sulfonic acid groups was lengthened to different levels compared with the one in the isolated cation. The ionic liquid [(PS)2bPy][OTf]2 with the shortest H–O bond distance had the strongest hydrogen bond and hence showed the strongest acidity and the highest catalytic activity.
Co-reporter:Yuanyuan Wang, Junlong Zhou, Kun Liu, Liyi Dai
Journal of Molecular Catalysis A: Chemical 2013 Volume 366() pp:195-201
Publication Date(Web):January 2013
DOI:10.1016/j.molcata.2012.09.023
A series of novel bi-SO3H-functionalized ionic liquids were synthesized and acted as catalysts for the synthesis of β-acetamido ketones. Compared with traditional single-SO3H-functionalized ionic liquids, less amount of catalysts, higher yields and shorter reaction time are the key features of this methodology. Hammett function values and the minimum-energy geometries of bi-SO3H-functionalized ILs were calculated and the results revealed that the acidities and catalytic activities of ILs in synthesis of β-acetamido ketones were influenced by their structures. The IL [(PS)2pi][OTf]2 with the shortest HO bond distance had the strongest acidity and the highest catalytic activity.Graphical abstractHighlights► Several bi-SO3H-functionalized ionic liquids (BSFILs) were developed. ► BSFILs exhibited higher activities compared to single-SO3H-functionalized ILs. ► IL with shorter hydrogen bond had stronger acidity and higher catalytic activity. ► Low cost, high yields, short reaction times were the key features of this method.
Co-reporter:Yuan Yuan Wang, Yue Tong Wu, Kun Liu, Li Yi Dai
Chinese Chemical Letters 2012 Volume 23(Issue 9) pp:1031-1034
Publication Date(Web):September 2012
DOI:10.1016/j.cclet.2012.06.043
In this article, series of novel bi-SO3H-functionalized ILs were synthesized using simple, efficient and economic procedure. Hammett method had been used to determine the acidity order of these ionic liquids, and the acidities of bi-SO3H-functionalized ILs were stronger than that of traditional single-SO3H-functionalized ILs. Their catalytic activities in the synthesis of N-(3-phenyl)-3-oxo-1-(phenylpropyl)acetamide were investigated and they were consistent with their acidities.
Co-reporter:Yuanyuan Wang;Yuetong Wu;Yu Wang ;Liyi Dai
Chinese Journal of Chemistry 2012 Volume 30( Issue 8) pp:1709-1714
Publication Date(Web):
DOI:10.1002/cjoc.201200181
Abstract
An efficient and environmentally benign procedure for the reactions of three components condensation of salicylaldehyde and two different CH acids to give 2-amino-4H-chromenes catalyzed by a series of basic-functionalized ionic liquids was reported. The most possible reaction pathway was proposed for the first time by performing density functional theory (DFT) calculations. Both cation and anion of [Bmim]OH have a cooperative effect on the reaction. [Bmim]+ increases the electrophilicity of salicylaldehyde via intermolecular hydrogen bonds, while OH− deprives proton of two CH acids to strengthen their nucleophilic ability.
Co-reporter:Yong-Juan Chang;Zhi-Zhong Wang;Li-Gang Luo;Li-Yi Dai
Chemical Papers 2012 Volume 66( Issue 1) pp:33-38
Publication Date(Web):2012 January
DOI:10.2478/s11696-011-0093-3
We performed the Rupe rearrangement of 1-ethynylcyclohexan-1-ol in near-critical water to study the reaction under high temperature conditions. The final product thus obtained was primarily 1-cyclohexen-1-ylethanone which was identified by GC-MS. The influences of reaction time, temperature, and initial reactant-to-water ratio on the yield of 1-cyclohexen-1-ylethanone were examined. The yield of 1-cyclohexen-1-ylethanone was 49 % in pure water at 260°C for a reaction time of 60 min. However, when additives such as ZnSO4, FeCl3, and NaHSO4, respectively, were introduced to the water to investigate the effect of salts on the Rupe rearrangement reaction, the yield increased markedly to as much as 88 % in 5 mole % NaHSO4 aqueous solution under the same conditions. The catalytic ability of the additives decreased in order: NaHSO4, FeCl3, ZnSO4. On the basis of these results, a possible reaction mechanism of the Rupe rearrangement of 1-ethynylcyclohexan-1-ol in near-critical water was proposed.
Co-reporter:Xinxin Gong;Yuanyuan Wang;Yu Wang ;Liyi Dai
Chinese Journal of Chemistry 2011 Volume 29( Issue 5) pp:968-972
Publication Date(Web):
DOI:10.1002/cjoc.201190197
Abstract
2-Substituted benzimidazoles have been synthesized in excellent yields under solvent-free conditions using a series of acidic ionic liquids as catalysts. The results indicate that SO3H-functionalized ionic liquids show higher catalytic activities than other acidic ionic liquids. The effects of reaction conditions such as the amounts of ionic liquids, the ratio of reactants were investigated. A Hammett method was used to determine the acidity order of these ionic liquids and the results were found to be relevant to the catalytic activities observed in the synthesis reaction. Besides, the reaction mechanism was stimulated using DFT method.
Co-reporter:Shuang Li, Yong Juan Chang, Yu Wang, Li Yi Dai
Chinese Chemical Letters 2011 Volume 22(Issue 4) pp:393-396
Publication Date(Web):April 2011
DOI:10.1016/j.cclet.2010.11.003
The hydration of phenylacetylene in near-critical water, assisted with additives (NaHSO4, ZnCl2, FeCl3), has been successfully conducted with temperature and residence time ranges of 220–300 °C and 60–180 min, respectively. The results showed the catalytic ability is FeCl3 > ZnCl2 > NaHSO4. The maximum yield of product acetophenone was 96.68% at 260 °C, 120 min. Based on the results found, a possible mechanism of hydration of phenylacetylene in near-critical water was proposed.
Co-reporter:Yuan Yuan Wang, Yan Nan Xu, Zhi Zhong Wang, Li Yi Dai
Chinese Chemical Letters 2010 Volume 21(Issue 5) pp:524-528
Publication Date(Web):May 2010
DOI:10.1016/j.cclet.2009.12.014
In this article, an efficient, simple and environmentally friendly approach to the synthesis of diacetals (diketals) pentaerythritol using SO3H-functionalized ionic liquids (ILs) as catalysts was reported. The ILs show high catalytic activity and reusability with good to excellent yields of the desired products. Hammett method has been used to determine the acidity order of these ionic liquids and the results are consistent with the catalytic activities observed in acetalization reaction. Maximum product yield of 93% was observed on using [PSPy][OTf] as catalyst and it can be reused at least 8 times without obvious activity loss.
Co-reporter:Yuanyuan Wang, Xinxin Gong, Zhizhong Wang, Liyi Dai
Journal of Molecular Catalysis A: Chemical 2010 322(1–2) pp: 7-16
Publication Date(Web):
DOI:10.1016/j.molcata.2010.01.011
Co-reporter:Dong Jiang, Yuan Yuan Wang, Yan Nan Xu, Li Yi Dai
Chinese Chemical Letters 2009 Volume 20(Issue 3) pp:279-282
Publication Date(Web):March 2009
DOI:10.1016/j.cclet.2008.12.005
Ionic liquids [Bmim]BF4 and [Bpy]BF4 were employed as environmentally benign media in Doebner condensation to synthesize α, β-unsaturated carboxylic acid. The good results showed that [Bmim]BF4 and [Bpy]BF4 were efficient media for Doebner condensation, which could be recycled easily. The highest yields could reach 93% and 90% in [Bmim]BF4 and [Bpy]BF4, respectively.
Co-reporter:P.-G. Duan;S. Li;Y. Yang;Z.-Z. Wang;L.-Y. Dai
Chemical Engineering & Technology 2009 Volume 32( Issue 5) pp:771-777
Publication Date(Web):
DOI:10.1002/ceat.200800607
Abstract
Hydrolysis of 5-cyanovaleramide (5-CVAM) in near-critical water without the addition of any catalyst has been demonstrated. The results demonstrated that the cyano group at one end of the carbon of 5-CVAM is more reactive than the amide group at the other end, under the same experimental conditions. The relations between 5-CVAM concentration and residence time revealed that hydrolysis of 5-CVAM shows second-order reaction kinetics in the investigated temperature range. The rate constants, average apparent activation energy and pre-exponential factor were evaluated according to the Arrhenius equation. Based on the experimental results, a carbon balance was calculated, and a hydrolysis reaction scheme of 5-CVAM was proposed.
Co-reporter:Peigao Duan;Yuanyuan Wang;Yan Yang;Liyi Dai
Journal of Solution Chemistry 2009 Volume 38( Issue 2) pp:241-258
Publication Date(Web):2009 February
DOI:10.1007/s10953-008-9362-3
A study of the hydrolysis of adiponitrile (ADN) was performed in subcritical water to research the dependence on experimental conditions. An L25(56) orthogonal array design (OAD) with six factors at five levels using statistical analysis was employed to optimize the experimental conditions for each product in which the interactions between the variables were temporarily neglected. The six factors were adiponitrile concentration (ADN c, wt%), temperature (T), time (t h), percentage of additives (reactant/additive, wt/wt%), additives (A), and pressure (p, MPa). The effects of these parameters were investigated using the analysis of variance (ANOVA) to determine the relationship between experimental conditions and yield levels of different products. The results showed that (ADN c) and T had a significant influence on the yields of adipamide, adipamic acid, and adipic acid at p<0.05. Time was the statistically significant factor for the yield of 5-cyanovalermic acid at p<0.05 and (ADN c) was the significant factor for the yield of 5-cyanovaleramide at p<0.1. Finally, five supplementary experiments were conducted under optimized conditions predicted by the Taguchi method; the results showed that the yield obtained of each product was no lower than that of the highest in the 25 experiments. Carbon balance was calculated to demonstrate the validity of the experimental technique and the reliability of the results. Based on the experimental results, a possible reaction mechanism was proposed.
Co-reporter:Yuan-Yuan WANG;Wei LI;Li-Yi DAI
Chinese Journal of Chemistry 2008 Volume 26( Issue 8) pp:1390-1394
Publication Date(Web):
DOI:10.1002/cjoc.200890253
Abstract
Cyclodehydration of diethylene glycol using various Brønsted acidic ionic liquids as dual solvent-catalysts was studied for the first time. Better results were obtained in the presence of 1-butyl-3-methylimidazolium hydrogen sulfate ([SPmim]HSO4) than other Br?nsted acidic ionic liquids. The effects of reaction conditions such as reaction temperature, reaction time and molar ratio of ionic liquid/diethylene glycol were investigated. Good conversion rate and high selectivity were obtained in ionic liquid [SPmim]HSO4 under the optimum conditions. A 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.
Co-reporter:Pei-Gao DUAN;Yan-Lei NIU;Yuan-Yuan WANG ;Li-Yi DAI
Chinese Journal of Chemistry 2008 Volume 26( Issue 9) pp:1741-1744
Publication Date(Web):
DOI:10.1002/cjoc.200890315
Abstract
Hydrolysis of adiponitrile (ADN) in near-critical water was successfully conducted in a batch reactor. Influences of m(AND)/m(water) ratio, temperature, time, m(AND)/m(additive) ratio, kind of additive and pressure on the yield of each product were investigated. Five compounds resulting from the hydrolysis of ADN, including 5-cyanovaleramide, adipamide, adipamic acid, adipic acid and trace of 5-cyanovaleric acid, were detected by high performance liquid chromatography. The results showed that change of ADN concentration and temperature had significant influences on the yields of adipamide, adipamic acid and adipic acid; time was the significant factor for the yield of 5-cyanovaleric acid; and the yield of 5-cyanovaleramide was more dependent on the ADN concentration.
Co-reporter:Dong Jiang;Yuan Yuan Wang;Ming Tu
Reaction Kinetics, Mechanisms and Catalysis 2008 Volume 95( Issue 2) pp:265-271
Publication Date(Web):2008 December
DOI:10.1007/s11144-008-5345-8
Four novel Brönsted acidic ionic liquids with two different acid sites on the imidazolium cations were synthesized and employed as catalysts and media in the esterification of acetonitrile with alcohols. The results showed that [HSO3-pHim]HSO4 was the most efficient catalyst and medium which could be recycled easily without obvious decline in the catalytic activity.
Co-reporter:Dong Jiang;Yuan Yuan Wang
Reaction Kinetics, Mechanisms and Catalysis 2008 Volume 93( Issue 2) pp:257-263
Publication Date(Web):2008 April
DOI:10.1007/s11144-008-5229-2
Brönsted acidic ionic liquids were employed as a series of efficient catalysts and solvents in the esterification of alcohols with acetic anhydride at room temperature. Good yields, mild reaction conditions, short reaction time and no side reactions were achieved. The ionic liquids could be recycled easily without obvious decline in catalytic activities.
Co-reporter:Yuan-Yuan Wang;Wei Li;Li-Yi Dai
Chemical Papers 2008 Volume 62( Issue 3) pp:313-317
Publication Date(Web):2008 June
DOI:10.2478/s11696-008-0028-9
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.
Co-reporter:Yuan Yuan Wang, Rong Wang, Liang Chun Wu, Li Yi Dai
Chinese Chemical Letters 2007 Volume 18(Issue 1) pp:24-26
Publication Date(Web):January 2007
DOI:10.1016/j.cclet.2006.11.023
Fructone (2-methyl-2-ethylacetoacetate-1, 3-dioxolane), a flavouring material, has been synthesized from ethyl acetoacetate and glycol using five water-soluble Brønsted acid ionic liquids as catalysts for the first time. The used Brønsted acid ionic liquids include [Hmim]Tfa, [Hmim]Tsa, [Hmim]BF4, [Bmim]HSO4, [Bmim]H2PO4, and [Hmim]BF4 showed the highest catalytic activity for the preparation of fructone. After reaction, the product could be isolated from the reaction system automatically, and the ionic liquid could be directly reused without dehydration.
Co-reporter:P.-G. Duan;X. Wang;L.-Y. Dai
Chemical Engineering & Technology 2007 Volume 30(Issue 2) pp:
Publication Date(Web):25 JAN 2007
DOI:10.1002/ceat.200600298
The hydrolysis of iminodiacetonitrile (IDAN) in near-critical water, without added catalysts, has been successfully conducted with temperature and residence time ranges of 200–260 °C and 10–60 min, respectively. The effects of temperature, pressure, and initial reactant/water ratio on the reaction rate and yield have been investigated. The final reaction products primarily included iminodiacetic acid (IDA) and ammonia associated with other by-products; gas formation was negligible. The maximum yield of IDA was 92.3 mol.-% at 210 °C and 10 MPa, with a conversion of almost 100 %.The apparent activation energy and ln A of IDAN hydrolysis were evaluated as 45.77 ± 5.26 kJ/mol and 8.6 ± 0.1 min–1, respectively, based on the assumption of first-order reaction. The reaction mechanism and scheme were similar to those of base-catalyzed reactions of nitriles examined in less severe conditions.
Co-reporter:Yuan-Yuan Wang;Wei Li;Cheng-Di Xu;Li-Yi Dai
Chinese Journal of Chemistry 2007 Volume 25(Issue 1) pp:
Publication Date(Web):8 JAN 2007
DOI:10.1002/cjoc.200790019
A novel Brønsted acid task specific ionic liquid 1-ethylbenzimidazolium tetrafluoroborate ([Hebim]BF4) with functional benzimidazolium cation was synthesized and characterized by 1H NMR, IR, MS spectra and elemental analysis. This novel ionic liquid was successfully used as dual solvent-catalyst for the synthesis of arylic esters. Higher yields were obtained in the presence of [Hebim]BF4 in comparison with other imidazolium ionic liquids because of the good solubility of the aromatic alcohols and aromatic carboxylic acids in [Hebim]BF4. The product could be separated conveniently from the reaction system, and the ionic liquid could be easily reused after removal of water under vacuum. After 10 times reuse, the selectivity of the ester was still 100%.
Co-reporter:Yuan Yuan Wang, Wei Li, Li Yi Dai
Chinese Chemical Letters 2007 Volume 18(Issue 10) pp:1187-1190
Publication Date(Web):October 2007
DOI:10.1016/j.cclet.2007.08.013
Cationic ring-opening polymerization of 3,3-bis(chloromethyl)oxacyclobutane catalyzed by BF3·OEt2 was carried out in ionic liquids [bmim]BF4 and [bmim]PF6. The influences of BCMO concentration and molar ratio of BCMO/ BF3·OEt2 on the molecular weights and yield of PBCMO were investigated. The polymerization in ionic liquids proceed to high conversions, although molecular weights are limited, similar to polymerization in organic solvent such as CH2Cl2. Follow a viewpoint of green chemistry, we feel ionic liquid [bmim]BF4 is superior to [bmim]PF6. Extracting [bmim]PF6 from the product using organic solvent as extractant limits its advantage as a green reaction media.
Co-reporter:Yuan-Yuan Wang;Dong Jiang;Rong Wang;Li-Yi Dai
Reaction Kinetics, Mechanisms and Catalysis 2007 Volume 90( Issue 1) pp:69-76
Publication Date(Web):2007 February
DOI:10.1007/s11144-007-4999-2
Cationic copolymerization of 1,3-pentadiene (PD) with styrene (St) using the triethylamine hydrochloride-aluminium chloride (Et3NHCl-AlCl3) room temperature ionic liquid as an initiator in toluene has been investigated. The polymerization proceeds to high conversions, indicating high initiating reactivity of Et3NHCl-AlCl3 in these copolymerization systems, although molecular weights of the polymers are limited which are similar to polymerization initiated by Lewis acids such as TiCl4, BF3, BF3·OEt2. The polymers were analyzed using IR spectra in conjunction with gel permeation chromatography (GPC).
Co-reporter:Kun Liu, Zhaoxiang Chen, Peipei Zou, Yuanyuan Wang, Liyi Dai
Catalysis Communications (5 July 2015) Volume 67() pp:54-58
Publication Date(Web):5 July 2015
DOI:10.1016/j.catcom.2015.04.001
•CuPd–Cu2O/Ti-powder is prepared using a simple impregnation method.•CuPd–Cu2O/Ti-powder exhibits excellent activity and stability after activation.•CuPd(alloy)–Cu2O formed during the reaction contributes to the activity and stability.The oxidation of alcohols to carbonyl compounds in gas-phase is of great importance in organic chemistry and industrial process. Herein, the catalyst CuPd–Cu2O/Ti-powder is prepared by depositing Cu(NO3)2 and Pd(NO3)2 on Ti powder support followed by in-situ activation in reaction stream, which delivers high-performance for the gas-phase oxidation of alcohols. Compared with Cu/Ti-powder and Pd/Ti-powder, CuPd–Cu2O/Ti-powder exhibits higher stability and activity in alcohol oxidation reaction. The catalyst is characterized by XRD, XPS, TEM and ICP. The results indicate that CuPd(alloy)–Cu2O formed during the reaction contributes to the high activity and stability.Download full-size image
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