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Geometric effect promoted hydrotalcites catalysts towards aldol condensation reaction 被引量:4
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作者 Huimin Wang Weihan Bing +8 位作者 Chunyuan Chen Yusen Yang Ming Xu Lifang Chen Lei Zheng Xiaolin Li Xin Zhang Jianjun Yin Min Wei 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第8期1279-1287,共9页
In solid basic catalysis field,how to achieve optimized activity and desired stability through elaborate control over basic site properties remains a challenge.In this work,taking advantage of the structure memory eff... In solid basic catalysis field,how to achieve optimized activity and desired stability through elaborate control over basic site properties remains a challenge.In this work,taking advantage of the structure memory effect of layered double hydroxides(LDHs),rehydrated Ca4 Al1-x Gax-LDHs and Ca4 Al1-x Inx-LDHs catalysts were prepared and applied in aldol condensation reaction that isobutyraldehyde(IBD)reacts with formaldehyde(FA)to obtain hydroxypivalaldehyde(HPA).Notably,the resulting re-Ca4 Al0.90Ga0.10-LDHs exhibits an extraordinarily-high catalytic activity(HPA yield:72%),which is to our best knowledge the highest level in this reaction.The weak Br?nsted basic site,7-coordinated Ca-OH group,which serves as an active site,catalyzes the condensation process and promotes the product desorption.Studies on structure-property correlations demonstrate that Ga as a structural promoter induces a moderate expansion of the laminate lattice,which results in a significant increase in the concentration of weak basic sites in re-Ca4Al0.90Ga0.10-LDHs,accounting for its high catalytic activity.This work illuminates that geometric structure of basic active sites can be tuned via introducing catalyst additive,which leads to a largely improved performance of hydrotalcite solid basic catalysts towards aldol condensation reaction. 展开更多
关键词 Solid basic catalyst Geometric structure Structural promoter aldol condensation Reconstructed hydrotalcite material
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HZSM-35 zeolite catalyzed aldol condensation reaction to prepare acrylic acid and its ester:Effect of its acidic property 被引量:4
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作者 Zhanling Ma Xiangang Ma +4 位作者 Youming Ni Hongchao Liu Wenliang Zhu Xinwen Guo Zhongmin Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第11期1762-1769,共8页
Acrylic acid(AA)and its ester,methyl acrylate(MA),were produced by a green one‐step aldol condensation reaction of dimethoxymethane and methyl acetate.The reaction was conducted over ZSM‐35 zeolites with different c... Acrylic acid(AA)and its ester,methyl acrylate(MA),were produced by a green one‐step aldol condensation reaction of dimethoxymethane and methyl acetate.The reaction was conducted over ZSM‐35 zeolites with different concentrations of Bronsted acid,which were prepared by the sodium ion‐exchange process with H‐form zeolite.The acidic property of HZSM‐35 was studied in detail through infrared experiments.About 51%of all bridging OH groups were distributed in cages,while 23%and 26%,respectively,were distributed in 10‐and 8‐ring channels.The catalytic performance was enhanced by a high concentration of Bronsted acid,indicating that Bronsted acid is an active site for the aldol condensation reaction.The ZSM‐35 zeolite possessing a concentration of Bronsted acid as high as 0.049 mmol/g demonstrated excellent performance with a MA+AA selectivity of up to 73%. 展开更多
关键词 aldol condensation Methyl acetate ZSM‐35 zeolite Bronsted acid Acrylic acid
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Highly efficient Nb2O5 catalyst for aldol condensation of biomass-derived carbonyl molecules to fuel precursors 被引量:3
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作者 Yaxuan Jing Yu Xin +2 位作者 Yong Guo Xiaohui Liu Yanqin Wang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第8期1168-1177,共10页
Aldol condensation is of significant importance for the production of fuel precursors from biomass- derived chemicals and has received increasing attention. Here we report a Nb2O5 catalyst with excellent activity and ... Aldol condensation is of significant importance for the production of fuel precursors from biomass- derived chemicals and has received increasing attention. Here we report a Nb2O5 catalyst with excellent activity and stability in the aldol condensation of biomass-derived carbonyl molecules. It is found that in the aldol condensation of furfural with 4-heptanone, Nb2O5 has obviously superior activity, which is not only better than that of other common solid acid catalysts (ZrO2 and Al2O3), more importantly, but also better than that of solid base catalysts (MgO, CaO, and magnesium- aluminum hydrotalcite). The detailed characterizations by N2 sorption/desorption, NH3-TPD, Py-FTIR and DRIFTS study of acetone adsorption reveal that Nb2O5 has a strong ability to activate the C=O bond in carbonyl molecules, which helps to generate a metal enolate intermediate and undergo the nucleophilic addition to form a new C–C bond. Furthermore, the applicability of Nb2O5 to aldol condensation is extended to other biomass-derived carbonyl molecules and high yields of target fuel precursors are obtained. Finally, a multifunctional Pd/Nb2O5 catalyst is prepared and successfully used in the one-pot synthesis of liquid alkanes from biomass-derived carbonyl molecules by combining the aldol condensation with the sequential hydrodeoxygenation. 展开更多
关键词 aldol condensation NB2O5 C=O activation Fuel precursor Bio-liquid alkane One-pot process
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Aldol Condensation of Acetylferrocene under Ultrasound 被引量:3
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作者 Shun Jun JI, Zhi Liang SHEN, Shun Yi WANG College of Chemistry and Chemical Engineering, Suzhou University, Suzhou 215006 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第7期663-666,共4页
Aldol condensation of acetylferrocene with aromatic aldehydes afforded ferroceny- lenones in 76%-92% yields under ultrasound at room temperature.
关键词 ACETYLFERROCENE aldol condensation ferrocenylenone ultrasonic irradiation.
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THE SOLID STATE ALDOL CONDENSATION REACTION OF ACETYLFERROCENE AND AROMATIC ALDEHYDES 被引量:2
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作者 Ji Ben MEIG Hong MA Yong Mei WANG Department of Chemistry,Nankai University,Tianjin,300071 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第6期475-478,共4页
The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in sol... The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in solution and eight compounds have been prepared. Their structures have been characterized by UV,IR,1~HNMR,HS and elemental analysis. 展开更多
关键词 OC THE SOLID STATE aldol condensation REACTION OF ACETYLFERROCENE AND AROMATIC ALDEHYDES
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Study on Aldol Condensation of HCHO and CH_3CHO over MgO Catalysts Modified by Lanthanum and Cerium
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作者 王幸宜 李春香 杨菊群 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第6期848-853,共6页
Aldol condensation of HCHO and CH_3CHO over MgO, modified MgO and Al_2O_3 with rare earth oxides, was studied. The measurement of adsorption of pyrrole on catalysts by in-situ FT-IR and NH_3 TPD indicated that the add... Aldol condensation of HCHO and CH_3CHO over MgO, modified MgO and Al_2O_3 with rare earth oxides, was studied. The measurement of adsorption of pyrrole on catalysts by in-situ FT-IR and NH_3 TPD indicated that the addition of elements La or Ce into MgO increased the acidity of the solid. In-situ FT-IR showed that the activation of-C=O in HCHO adsorbed on CeO-MgO and La_2O_3-MgO occurred. The measurement of catalytic activity implied that the modified catalysts can promote the formation of pentaerythritol, dipentaerthritol and tripentaerythritol. 展开更多
关键词 aldol condensation FORMALDEHYDE ACETALDEHYDE MGO Al_2O_3 CERIUM LANTHANUM rare earths
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Functioned Calix[4]arenes as Artificial Enzymes Catalyze Aldol Condensation
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作者 Li LIU Zu Xing YANG +1 位作者 Yu Liang WANG Shu Hua CHEN(Faculty of Chemistry, Sichuan University Chengdu 610064) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第6期485-488,共4页
Aldolase models derived from calix[4]arene were designed and synthesized. The aldol condensation of p-nitrobenzaldehyde with acetone was catalyzed by the synthetic enzymes proceeded under mild conditions to offer chie... Aldolase models derived from calix[4]arene were designed and synthesized. The aldol condensation of p-nitrobenzaldehyde with acetone was catalyzed by the synthetic enzymes proceeded under mild conditions to offer chiefly aldol-type product in good yield. 展开更多
关键词 CALIXARENE artificial enzyme aldol condensation CATALYSIS
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InCl_3·4H_2O Catalyzed Aldol Condensation of Cycloalkanones with Aromatic Aldehydes
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作者 Gui Sheng DENG Tie Gang REN 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第10期859-860,共2页
InCl34H2O catalyzes the cross-aldol condensation of cycloalkanones with aromatic aldehydes in sealed tube under solvent free condition to afford an efficient method for the synthesis of a, a-bis(substituted)benzyliden... InCl34H2O catalyzes the cross-aldol condensation of cycloalkanones with aromatic aldehydes in sealed tube under solvent free condition to afford an efficient method for the synthesis of a, a-bis(substituted)benzylidenecycloalkanones. 展开更多
关键词 aldol condensation cycloalkanone indium trichloride catalysis.
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Cooperative catalytic effects between the penta-coordinated Al and Al_(2)O_(3)in Al_(2)O_(3)-AlPO_(4)for aldol condensation of methyl acetate with formaldehyde to methyl acrylate
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作者 Zhenyu Wu Zengxi Li Chunshan Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第12期172-183,共12页
The bare amorphous Al_(2)O_(3)-AlPO_(4)and Cs/Al_(2)O_(3)-AlPO_(4)catalysts were developed for the aldol condensation of methyl acetate with formaldehyde to methyl acrylate.The structure and property of catalyst were ... The bare amorphous Al_(2)O_(3)-AlPO_(4)and Cs/Al_(2)O_(3)-AlPO_(4)catalysts were developed for the aldol condensation of methyl acetate with formaldehyde to methyl acrylate.The structure and property of catalyst were characterized by XRD,XPS,BET,Pyridine-IR,FT-IR,^(27)Al-MASNMR,NH_(3)-/CO_(2)-TPD and SEM.The correlation between structural features and acid-base properties was established,and the loading effect of the cesium species was investigated.Due to cooperative catalytic effects between the penta-coordinated Al and Al_(2)O_(3),the weak-Ⅱacid and medium acid site densities and the product selectivity were improved.While the basic site densities of these catalysts were almost in proportion to the conversion of methyl acetate.The loaded Cs could form new basic sites and change the distribution of acid sites which further enhance the catalytic performance.As a result,the 10Cs/8AlP was proved to be an optimal catalyst with the yield and selectivity of 21.2%and 85%for methyl acrylate respectively.During the reaction,a deactivation behavior was observed on 10Cs/8AlP catalyst due to the carbon deposition,however,it could be regenerated by thermal treatment in the air atmosphere at 400℃. 展开更多
关键词 Methyl acrylate(MA) aldol condensation Al_(2)O_(3)-AlPO_(4) Penta-coordinated aluminum Cooperative effects
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FUNCTIONALIZED CYCLODEXSTRINS BEARING AM INOALKYLIMINO GROUPS AS ACTIVE CENTERS TO CATALYZE ALDOL CONDENSATIONS
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作者 De Qi YUAN Ru Gang XIE Hua Ming ZHAO 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第8期617-620,共4页
Efficient catalysis of functinnatized β-cyctodextrins bearing aninoatkytimino groups for atdot condensations of nitrobenzatdehydes and acetone has been effected and substantiated by preparative experiments
关键词 NBA FUNCTIONALIZED CYCLODEXSTRINS BEARING AM INOALKYLIMINO GROUPS AS ACTIVE CENTERS TO CATALYZE aldol condensationS AS AM
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Intramolecular Aldol Condensation ofα- Oxo Ketene Dibenzylthioacetals: A Facile Route to Substituted Thiophenes
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作者 Mang WANG Qun LIU +1 位作者 Mei Xing ZHAO Li Min WANG (Department of Chemistry, Northeast Normal University, Changchun 130024) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第1期3-4,共2页
A new method for the synthesis of substituted thiophenes was through intramolecular aldol condensation ofα-oxo ketene dibenzylthioacetals.All products were confirmed with IR, 1 H NMR and elemental analysis.
关键词 α-Oxo ketene dibenzylthioacetals substituted thiophenes intramolecular aldol condensation.
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Synthesis of straight-chain C_(49)H_(100) alkane using a modular splicing strategy
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作者 Bing Ma Jingqing Tian +3 位作者 Xueling Lang Shutao Lei Bolong Li Chen Zhao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期414-421,共8页
Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point waxes.Unlike conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and p... Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point waxes.Unlike conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and polyethylene cracking)typically resulting in wide n-alkane distributions,the elaborate design strategy presented herein allows the direct synthesis of pure,long n-alkanes using a modular splicing method with acetone,furfural,and fatty acid anhydrides or acyl chlorides as bio-blocks.The herein approach is based on a simple four-step catalytic reaction scheme involving C–C chain elongation and C–O bond activation.The synthesized pure n-alkanes had a carbon chain length as high as C_(49)(total yield of 49%).The synthesis approach also allows to selectively prepare n-alkanes with even and odd carbon numbers ranging from C15 to C_(49).This process represents a great breakthrough in the synthesis of long-chain pure n-alkanes,surpassing the carbon number limitations reported in previous methodologies. 展开更多
关键词 Straight-chain alkane aldol condensation F-Cacylation HYDRODEOXYGENATION
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α,β-Dehydroamino Acid Synthesis through Proline-Catalyzed Aldol Condensation with a Glycine Schiff Base
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作者 Jun Sawamura Daikan Ieiri +1 位作者 Ryo Yazaki Takashi Ohshima 《Precision Chemistry》 2024年第1期14-20,共7页
A general protocol for the synthesis ofα,β-dehydroamino acids and their peptides was developed.Proline efficiently catalyzed an aldol condensation reaction of a glycine Schiff base with a variety of aldehydes.The hy... A general protocol for the synthesis ofα,β-dehydroamino acids and their peptides was developed.Proline efficiently catalyzed an aldol condensation reaction of a glycine Schiff base with a variety of aldehydes.The hydroxy group on the benzophenone imine was crucial for high Z/E selectivity and further transimination for protecting group-freeα,β-dehydroamino esters.Peptide elongation of both the C-and N-terminals highlighted the usefulness of our present protocol. 展开更多
关键词 α β-dehydroamino acid PEPTIDE PROLINE aldol condensation glycine Schiff base transimination
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Efficient Synthesis of Dicycloalkenopyridines:One-pot Multicomponent Condensation of Aldehydes with Cyclic Ketones
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作者 CAI Xi-mei WANG Qi-fang YAN Chao-guo 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2009年第5期657-661,共5页
Under microwave irradiation, the one-pot multicomponent condensation reaction of three moles of aromatic aldehydes with two moles of cyclic ketones having free a,a'-methylene positions such as cyclopentanone or cyclo... Under microwave irradiation, the one-pot multicomponent condensation reaction of three moles of aromatic aldehydes with two moles of cyclic ketones having free a,a'-methylene positions such as cyclopentanone or cyclohexanone in the presence of ammonium acetate and acetic acid afforded dicycloalkenopyridines with two a-arylidene groups in high yields. Under the similar reaction condition, the reaction of aromatic aldehydes with 1-tetralone having only one a-methylene position alternatively resulted in 10-aryl-2,3:5,6-dibenzoacridines. 展开更多
关键词 PYRIDINE ACRIDINE Microwave irradiation Aromatic aldehyde Cyclic ketone aldol condensation
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One-pot synthesis of cyclic aldol tetramer and ?, β-unsaturated aldol from linear aldehydes using quaternary ammonium combined with sodium hydroxide as catalysts
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作者 许海峰 钟宏 +1 位作者 王帅 李方旭 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第6期2081-2087,共7页
One-pot synthesis of cyclic aldol tetramer and α, β-unsaturated aldol from C3-C8 linear aldehydes using phase-transfer catalyst(PTC), quaternary ammonium, combined with sodium hydroxide as catalysts was investigat... One-pot synthesis of cyclic aldol tetramer and α, β-unsaturated aldol from C3-C8 linear aldehydes using phase-transfer catalyst(PTC), quaternary ammonium, combined with sodium hydroxide as catalysts was investigated. Butanal was subjected for detail investigations to study the effect of parameters. It was found that the selectivity of cyclic aldol tetramer depends greatly on the operating conditions of the reaction, especially the PTC/butanal molar ratio. The average selectivity of 2-hydroxy-6-propyl-l, 3, 5-triethyl-3-cyclohexene-1-carboxaldehyde(HPTECHCA) was 54.41% using tetrabutylammonium chloride combined with 14%(mass fraction) Na OH as catalysts at 60 ℃for 2 h with a PTC-to-butanal molar ratio of 0.09:1. Pentanal was more likely to generate cyclic aldol tetramer compared with other aldehydes under the optimum experimental conditions. Recovery of the PTC through water washing followed by adding enough sodium hydroxide from the washings was also demonstrated. 展开更多
关键词 aldol condensation one-pot synthesis phase-transfer catalyst ALDEHYDE
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Synthesis of high density and low freezing point jet fuels range cycloalkanes with cyclopentanone and lignin-derived vanillins
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作者 Xinghua Zhang Miaojia Song +3 位作者 Jianguo Liu Qi Zhang Lungang Chen Longlong Ma 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期22-30,共9页
In this work,a“cyclopentanone-vanillin”strategy was proposed for the preparation of jet fuel range cycloalkanes from lignocellulose-derived ketones and lignin-derived aldehydes via aldol condensation and hydrodeoxyg... In this work,a“cyclopentanone-vanillin”strategy was proposed for the preparation of jet fuel range cycloalkanes from lignocellulose-derived ketones and lignin-derived aldehydes via aldol condensation and hydrodeoxygenation(HDO).Ethanolamine lactate ionic liquid(LAIL)exhibited excellent catalytic activity in the aldol condensation of cyclopentanone and vanillin.Desired mono-condensation and bicondensation products were obtained with yield of 95.2%at 100℃.It is found that the synergy effects between amino group of ethanolamine and hydroxyl group of lactic acid play a key role in the aldol condensation.The condensation products were converted into cycloalkanes by HDO over 5%Pd/Nb_(2)O_(5)catalyst.The density of the obtained HDO products is 0.89 g/cm^(3)and the freezing point is lower than-60℃.These results suggest that the resulted cycloalkanes can be used as additives to improve the density and low-temperature fluidity of the jet fuels. 展开更多
关键词 aldol condensation Cyclopentanone-vanillin Ionic liquid catalysts HYDRODEOXYGENATION Jet fuel
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Reaction Mechanism of One-Step Conversion of Ethanol to 1,3-Butadiene over Zn-Y/BEA and Superior Catalysts Screening 被引量:2
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作者 Shu-Xuan Dang Han-Xuan Liu +4 位作者 Tao Ban Xin Gao Zheng-Qing Huang Dong-Yuan Yang Chun-Ran Chang 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第4期600-610,I0004-I0009,I0149,共18页
The one-step conversion of ethanol to 1,3-butadiene has achieved a breakthrough with the development of beta zeolite supported dual metal catalysts.However,the reaction mechanism from ethanol to butadiene is complex a... The one-step conversion of ethanol to 1,3-butadiene has achieved a breakthrough with the development of beta zeolite supported dual metal catalysts.However,the reaction mechanism from ethanol to butadiene is complex and has not yet been fully elucidated,and no catalyst screening effort has been done based on central metal atoms.In this work,density functional theory(DFT)calculations were employed to study the mechanism of one-step conversion of ethanol to butadiene over ZnY/BEA catalyst.The results show that ethanol dehydrogenation prefers to proceed on Zn site with a reaction energy of 0.77 eV in the rate-determining step,and the aldol condensation to produce butadiene prefers to proceed on Y site with a reaction energy of 0.69 eV in the rate-determining step.Based on the mechanism revealed,six elements were selected to replace Y for screening superior combination of Zn-M/BEA(M=Sn,Nb,Ta,Hf,Zr,Ti;BEA:beta polymorph A)for this reaction.As a result,Zn-Y/BEA(0.69 eV)is proven to be the most preferring catalyst compared with the other six ones,and Zn-Zr/BEA(0.85 eV),Zn-Ti/BEA(0.87 eV),and Zn-Sn/BEA(0.93 eV)can be potential candidates for the conversion of ethanol to butadiene.This work not only provides mechanistic insights into one-step catalytic conversion of ethanol to butadiene over Zn-Y/BEA catalyst but also offers more promising catalyst candidates for this reaction. 展开更多
关键词 ETHANOL 1 3-BUTADIENE Zn-Y/BEA aldol condensation Density functional theory
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Catalytic hydrotreatment of humins into cyclic hydrocarbons over solid acid supported metal catalysts in cyclohexane
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作者 Junmin Sun Hai Cheng +5 位作者 Yao Zhang Yinmin Zhang Xunfeng Lan Yongfeng Zhang Qineng Xia Daqian Ding 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第2期329-339,I0011,共12页
Humins are common undesirable sideproducts during many acid-catalyzed reactions in renewable biomass platform conversion. However, few studies have been reported to the efficient utilization of humins.For the first ti... Humins are common undesirable sideproducts during many acid-catalyzed reactions in renewable biomass platform conversion. However, few studies have been reported to the efficient utilization of humins.For the first time, the selective catalytic conversion of biomass-derived humins into cyclic hydrocarbons with high conversion rate and selectivity is presented using a home-made Ru/W-P-Si-O bifunctional catalyst. The multistage polymerization structure of humins was studied through controlled experiments.Results show that the CAC bond network can be efficiently depolymerized at a mild reaction temperature of 340–380 °C, catalyzed by the cooperative catalysis of nano-Ru particles and porous strong Lewis solid acid. Particularly, 95.4% conversion of humins was achieved under the optimal condition with up to 88.3%yield of cyclic hydrocarbons. The detailed composition after liquefaction was also analyzed. This study paves the way for the efficient production of cyclic and aromatic hydrocarbons from furan-derived humin polymer through Lewis acid-catalyzed Diels–Alder reactions between furan rings. 展开更多
关键词 Humins HYDROTREATMENT HYDRODEOXYGENATION Bifunctional catalyst Diels–Alder reaction Retro aldol condensation
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Selective C3-alkenylation of oxindole with aldehydes using heterogeneous CeO2 catalyst
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作者 MdNurnobi Rashed Abeda Sultana Touchy +4 位作者 Chandan Chaudhari Jaewan Jeon S.M.A.Hakim Siddiki Takashi Toyao Ken-ichi Shimizu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第6期970-976,共7页
We report herein that a commercially available CeO2 is an active and reusable catalyst for the C3-selective alkenylation of oxindole with aldehydes under solvent-free conditions. This catalytic method is generally app... We report herein that a commercially available CeO2 is an active and reusable catalyst for the C3-selective alkenylation of oxindole with aldehydes under solvent-free conditions. This catalytic method is generally applicable to different aromatic and aliphatic aldehydes, giving 3-alkyledene-oxindoles in high yields(87%–99%) and high stereoselectivities(79%–93% to E-isomers). This is the first example of the catalytic synthesis of 3-alkenyl-oxindoles from oxindole and various aliphatic aldehydes. The Lewis acid-base interaction between Lewis acid sites on CeO2 and benzaldehyde was studied by in situ IR. The structure-activity relationship study using CeO2 catalysts with different sizes suggests that defect-free CeO2 surface is the active site for this reaction. 展开更多
关键词 OXINDOLE ALDEHYDE aldol condensation C3-alkenylation CeO2 catalyst
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Formation of Pyrrolidin-1-ylcyclopentadienes via Cyclization of Alkyl 2-Dimethoxyacetyl-and 2-Ethoxalyl-4-oxopentanoates
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作者 ZHU Yi-qiang TANG Hui-tong ZHANG Pang 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1998年第2期23-29,共7页
The cyclizations of alkyl 2-dimethoxyacetyl and 2-ethoxalyl-4-oxopentanoates were only effected by means of pyrrolidine with the formation of appropriately substituted 1-pyrrolidin-1-ylcyclopentadienes.
关键词 Intramoleular aldol condensation ENAMINE Cyclopentadienamine
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