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SYNTHESIS OF DIARYL ETHERS THROUGH PHASE TRANSFER CATALYSIS WITH POTASSIUN FLUORIDE COATED ALUMINA AS A STRONG BASE
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作者 Ru Hong KANG Ji Sheng ZHU Wen Zi LI Shu Rong LIU Department of Chemistry,Hebei Normal University,Shijiazhuang 《Chinese Chemical Letters》 SCIE CAS CSCD 1990年第1期55-56,共2页
Seven diaryl ethers were synthesized with potassium fluoride coated alumina as a strong base and the addition of catalytic amount of PTC. The yield of diaryl ethers with addition of PTC was much higher than that witho... Seven diaryl ethers were synthesized with potassium fluoride coated alumina as a strong base and the addition of catalytic amount of PTC. The yield of diaryl ethers with addition of PTC was much higher than that without PTC.A discussion of the catalysis mechanism was given in this paper. 展开更多
关键词 TEBA SYNTHESIS OF DIARYL ETHERS THROUGH PHASE TRANSFER catalysis WITH POTASSIUN FLUORIDE COATED ALUMINA AS A STRONG base PTC AS
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Amine-grafted on lanthanide metal-organic frameworks:Three solid base catalysts for Knoevenagel condensation reaction 被引量:6
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作者 任颜卫 陆家贤 +2 位作者 江鸥 程晓飞 陈俊 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第11期1949-1956,共8页
A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er(btc)(ED)075(H2O)0.25 (2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine), Er(btc)(PP)0.5... A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er(btc)(ED)075(H2O)0.25 (2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine), Er(btc)(PP)0.55(H20)0.45 (3, PP = piperazine), and Er(btc)(DABCO)0.15(H2O)0.85 (4, DABCO = 1,4- diazabicyclo[2.2.2]octane), by grafting three different diamines onto the coordinatively unsaturated Er(III) ions into the channels of the desolvated lanthanide metal-organic framework (Er(otc)). The resulting metal-organic frameworks were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and N2 adsorption. Based on its higher loading ratio of the diamine, as well as its greater stability and porosity, catalyst 2 exhibited higher catalytic activity and reusability than catalysts 3 and 4- for the Knoevenagel condensation reaction. The catalytic mechanism of 2 has also been investigated using size-selective catalysis tests. 展开更多
关键词 Lanthanide metal-organic framework Post-synthetic modification Solid base catalystKnoevenagel condensation reaction Size-selective catalysis
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Oxidative coupling of alcohols and amines to an imine over Mg-Al acid-base bifunctional oxide catalysts 被引量:2
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作者 Jinling Song Guiyang Yu +4 位作者 Xi Li Xuwei Yang Wenxiang Zhang Wenfu Yan Gang Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第2期309-318,共10页
A series of Mg‐Al mixed oxide catalysts are prepared and introduced as efficient irreducible catalysts for the oxidative coupling of alcohols and amines to imine.The structure and surface properties of Mg‐Al oxides ... A series of Mg‐Al mixed oxide catalysts are prepared and introduced as efficient irreducible catalysts for the oxidative coupling of alcohols and amines to imine.The structure and surface properties of Mg‐Al oxides are modulated by changing the Mg/Al ratios,calcination temperature and treatment with probe molecules.Detailed characterization,including X‐ray diffraction,27Al magic angle spinning nuclear magnetic resonance spectroscopy,N2‐adsorption,NH3‐temperature‐programmed desorption,CO2‐temperature‐programmed desorption and X‐ray photoelectron spectroscopy are carried out to determine the physicochemical properties of these catalysts.The Mg‐Al oxides with Mg/Al=3exhibit the highest activity in the reaction,which possess a large number of surface weak basic sites and a relatively small number of weak acidic sites.The role of the acidic and basic sites in the reaction process is systematically investigated,and are shown to serve as adsorption and activation sites for amines and alcohols,respectively.Under the synergistic effect of these acid‐base centers,the oxidative coupling process successfully occurs on the surface of Mg‐Al mixed oxides.Compared with the acidic sites,the weak basic sites play a more important role in the catalytic process.The acidic sites are the catalytic centers for the benzyl alcohol activation,which control the reaction rate of the oxidative coupling reaction. 展开更多
关键词 Oxidative coupling Imine synthesis Alcohol oxidation Mg‐Al mixed oxides Acid‐base catalysis
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Lewis Base Catalyzed Selenofunctionalization of Alkynes with Acid-Controlled Divergent Chemoselectivity 被引量:1
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作者 Ling-Ling Chen Ren-Fei Cao +1 位作者 Hua Ke Zhi-Min Chen 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第14期1623-1629,共7页
Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time.Various selenium-containing tetrasubstituted alkenes were readi... Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time.Various selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z selectivities.As the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid. 展开更多
关键词 ALKYNES Electrophilic addition CHEMOSELECTIVITY Lewis base catalysis Selenofunctionalization
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Gas-phase dehydrochlorination of 1, 1, 2, 2-tetrachloroethane over the non-metal supported ionic liquid catalyst 被引量:2
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作者 Pengze Zhang Yangzhen Jin +3 位作者 Zhaobin Jiang Guanqun Xie Qunfeng Zhang Xiaonian Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第6期1623-1627,共5页
Developing of non-metallic catalyst to replace metal catalyst is a meaningful and challenging direction.In this work,the non-metallic catalyst was synthetized successfully by loading ionic liquid onto the silica surfa... Developing of non-metallic catalyst to replace metal catalyst is a meaningful and challenging direction.In this work,the non-metallic catalyst was synthetized successfully by loading ionic liquid onto the silica surface,which was applied for the gas-phase dehydrochlorination of 1,1,2,2-tetrachloroethane.The 12%TPPC/SiO2(wt%)showed the best results with the conversion of 1,1,2,2-tetrachloroethane reaching 100%.The selectivity of 1,1,2-trichloroethylene was 100%,and no deactivation was found during the evaluation period.The catalytic mechanism was investigated and possible reaction route was given,which was a reference for fabricating and design of solid base catalyst. 展开更多
关键词 Dehydrochlorination catalyst Supported ionic liquids Gas-phase catalysis base catalysis
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A catalysis study of mesoporous MCM-41 supported Schiff base and CuSO_4·5H_2O in a highly regioselective synthesis of 4-thiazolidinone derivatives from cyclocondensation of mercaptoacetic acid 被引量:2
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作者 Hai-Xia Pang Yong-Hai Hui +5 位作者 Kui Fan Xue-Jian Xing Yang Wu Jing-Hui Yang Wei Shi Zheng-Feng Xie 《Chinese Chemical Letters》 SCIE CAS CSCD 2016年第3期335-339,共5页
Mesoporous MCM-41 supported Schiff base and Cu SO4· 5H2 O shows high catalytic activity in the cyclocondensation of mercaptoacetic acid with imines(or aldehydes and amines) to afford pharmaceutically important ... Mesoporous MCM-41 supported Schiff base and Cu SO4· 5H2 O shows high catalytic activity in the cyclocondensation of mercaptoacetic acid with imines(or aldehydes and amines) to afford pharmaceutically important thiazolidinone derivatives. The catalytic reactions involving twocomponents or three-components afforded the desired product in high yields(up to 98% and 99%).Moreover, the catalyst works well with respect to recyclability, giving the product in 85% and 83% yields after recycling six times. 展开更多
关键词 MCM-41 Schiff base Cyclocondensation Mercaptoacetic acid catalysis
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Remote stereocontrol in the(4+2)cycloadditions of 1,7-zwitterions:Asymmetric synthesis of multifunctionalized tetrahydroquinoline derivatives
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作者 Chen Chen Jin Zhou +5 位作者 Jing Jiang Yang Li Ting Mao Cheng Peng Gu Zhan Wei Huang 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第1期222-226,共5页
The scope of stereochemistry recognition usually occurs near the chiral scaffold of a ligand or catalyst.Remote stereocontrol,which can surpass the limits of stereorecognition of remote prochiral centers,has long been... The scope of stereochemistry recognition usually occurs near the chiral scaffold of a ligand or catalyst.Remote stereocontrol,which can surpass the limits of stereorecognition of remote prochiral centers,has long been a challenging object of great interest in asymmetric catalysis.The current work realized the remote stereocontrol of 1,7-zwitterion intermediates formed from Huang's o-amino aryl MBH carbonates.With simple and easily accessibleβ-ICD as the bifunctional catalyst,multifunctionalized tetrahydroquinoline derivatives could be synthesized via(4+2)cycloadditions with excellent enantioselectivity and diastereoselectivity under mild conditions.The strategy possesses broad substrate scope,and three types of electron-deficient enones are successfully applied.Mechanistic studies disclosed the Lewis base-catalyzed reaction pathway,and H-bonding between the catalyst and enones is crucial for long-range stereocontrol.Scale-up reaction and transformations of the tetrahydroquinoline products demonstrated the potential of this strategy. 展开更多
关键词 Asymmetric synthesis TETRAHYDROQUINOLINE Remote stereocontrol PYRAZOLONE Lewis base catalysis 1 7-Zwitterion
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Efficient Synthesis of P-Chirogenic Compounds Enabled by Chiral Selenide-Catalyzed Enantioselective Electrophilic Aromatic Halogenation 被引量:2
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作者 Ruizhi Guo Ziqi Liu Xiaodan Zhao 《CCS Chemistry》 CAS 2021年第11期2617-2628,共12页
P-chirogenic compounds have been applied in different fields,especially in asymmetric catalysis as ligands and organocatalysts.However,broader applicability has been severely restricted by the lack of efficient synthe... P-chirogenic compounds have been applied in different fields,especially in asymmetric catalysis as ligands and organocatalysts.However,broader applicability has been severely restricted by the lack of efficient synthetic methods.Consequently,developing efficient methods to access these compounds is of high synthetic value.Herein,we report a convenient,efficient,and unprecedented pathway to construct valuable P-chirogenic compounds via chiral selenide-catalyzed enantioselective electrophilic aromatic halogenation.Using a new chiral bifunctional selenide as the catalyst,a variety of bis(2-hydroxyaryl)aryl phosphine oxides were efficiently converted to the corresponding chlorinated and brominated P-chirogenic compounds with good to excellent enantioselectivities.By slightly adjusting the catalyst and solvent,this method is also able to prepare chiral alkyl diaryl phosphine oxides and diaryl phosphinates.Furthermore,control experiments revealed the decomposition pathways of catalysts and the possible reasons why chiral selenide catalyst was more effective than chiral sulfide catalyst.The effect of hydrogen bonding was studied,and the reason why the chlorination took place on the various aromatic rings was elucidated when the substrates were switched from triaryl phosphine oxides to alkyl diaryl phosphine oxides and diaryl phosphinates. 展开更多
关键词 P-chirogenic compounds aromatic halogenation electrophilic reaction Lewis base catalysis asymmetric catalysis
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The cis-trans Isomerisation of Homologous 2-Hydroxycycloalkanecarboxylic Acids under Basic Conditions
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作者 GYARMATI Cs. Zsuzsanna PALINKO lstván +2 位作者 BOKROS Attila MARTINEK A. Tamás BERNATH Gábor 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2006年第12期1792-1795,共4页
The cis→trans isomerisation of homologous 2-hydroxycycloalkanecarboxylic acids in strongly basic aqueous solution was studied starting from the cis isomers. It was found that the cyclopentane, cyclohexane and cyclohe... The cis→trans isomerisation of homologous 2-hydroxycycloalkanecarboxylic acids in strongly basic aqueous solution was studied starting from the cis isomers. It was found that the cyclopentane, cyclohexane and cycloheptane homologues afforded synthetically useful amounts of the trans acids and the procedure resulted in relatively small quantities of the corresponding olefinic acids. In contrast, the isomerisation of the cis-2-hydroxycyclooctanecarboxylic acid produced roughly equal amounts of the cis and trans isomers and the 1-cyclooctenecarboxylic acid at equilibrium. Molecular modelling with the PM3 semiempirical method of the reactants, products and the intermediates applying explicit water molecules as reaction medium gave a fair estimate for the rate sequence of the idealised (dehydration-free) isomerisation reactions in aqueous base solution. 展开更多
关键词 geometric isomerisation base catalysis reaction mechanism molecular modelling
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Copper catalyzed/mediated direct B–H alkenylation/alkynylation in carboranes 被引量:2
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作者 Yu Chen Yik Ki Au +1 位作者 Yangjian Quan Zuowei Xie 《Science China Chemistry》 SCIE EI CAS CSCD 2019年第1期74-79,共6页
Base metal catalyzed regioselective cage B–H functionalization has been achieved. Under the assistance of a bidentate directing group, Cu-catalyzed [4+2] annulation of carboranyl amides with internal alkynes affords ... Base metal catalyzed regioselective cage B–H functionalization has been achieved. Under the assistance of a bidentate directing group, Cu-catalyzed [4+2] annulation of carboranyl amides with internal alkynes affords unprecedented C,B-substituted carborane-fused-pyridone derivatives, whereas the use of terminal alkynes leads to B–H/C(sp)–H dehydrocoupling products. The isolation and structural identification of a notably stable Cu(Ⅰ) intermediate shed light on the reaction mechanism, which is proposed to involve a Cu(Ⅲ) intermediate. 展开更多
关键词 [4+2] annulation ALKYNYLATION B-H activation base metal catalysis CARBORANE
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