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构筑开放锡位点实现酸性增强的二甲醚羰基化丝光沸石催化剂设计 被引量:1
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作者 Ying Li Man Yu +4 位作者 Guodong Qi Yunduo Liu Jing Lv Shouying Huang Xinbin Ma 《Engineering》 SCIE EI CAS CSCD 2024年第4期104-114,共11页
Due to their tunable acidity,shape selectivity,and excellent stability,zeolites are of great importance as solid acid materials in industrial catalysis.Tuning the properties of the acid sites in zeolites allows for th... Due to their tunable acidity,shape selectivity,and excellent stability,zeolites are of great importance as solid acid materials in industrial catalysis.Tuning the properties of the acid sites in zeolites allows for the rational design and fabrication of catalysts for target reactions.Dimethyl ether(DME)carbonylation,a critical chain-growth reaction for C1 resource utilization,is selectively catalyzed by the Brønsted acid sites within the eight-membered rings(8-MRs)of mordenite(MOR).It is anticipated that strengthening the Brønsted acidity—particularly in 8-MRs—will improve the catalytic performance of MOR.In this work,density functional theory(DFT)calculations are first employed and the results used to design a modified MOR with stannum(Sn)and to predict the corresponding changes in acidity.Guided by the theoretical studies,a series of Sn-modified MOR are synthesized via a defect-engineering and subsequent heteroatom-substitution strategy.After partial desilication,isolated tetrahedral Sn species in an open configuration are successfully synthesized for the first time,within which tetrahedrally coordinated Al sites are preserved.An acidic characterization is used to confirm that the acidity of the Brønsted acid sites is enhanced by the introduction of the Sn species;as a result,the sample exhibits excellent activity in DME carbonylation reaction.Kinetic and DFT studies reveal that this strengthened acidity facilitates the adsorption of DME and reduces the activation barriers of DME dissociation and acetyl formation,accounting for the improved activity.The work demonstrates mechanistic insights into the promoting effects of strong acidity on DME carbonylation and offers a promising strategy to precisely control the acidic strength of zeolites. 展开更多
关键词 ZEOLITE Sn modification CARBONYLATION Brønsted acid catalysis acidic strength
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Carbamate synthesis from amines and dialkyl carbonate over inexpensive and clean acidic catalyst—Sulfamic acid
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作者 Bo Wang Jing He Run Cang Sun 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第7期794-797,共4页
Sulfamic acid has been proved to be the most efficient and recyclable catalyst in carbamate synthesis from alkylamine and dialkyl carbonate.High selectivity,cost-efficiency and simple product separation were the advan... Sulfamic acid has been proved to be the most efficient and recyclable catalyst in carbamate synthesis from alkylamine and dialkyl carbonate.High selectivity,cost-efficiency and simple product separation were the advantageous features obtained in this process.Sulfamic acid could be reused several times and keep its initial activity in the recycle runs.In addition,sulfamic acid has also exhibited the potential catalytic ability for alkylation of aromatic amines. 展开更多
关键词 Sulfamic acid acidic catalysis CARBAMATE ALKYLAMINE Dimethyl carbonate
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SUIDIES ON SOME PROPERTIES AND CATALYSIS OF RARE EARTH HETEROPOLY ACIDS
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《Chemical Research in Chinese Universities》 SCIE CAS 1986年第1期93-96,共4页
INTRODUCTIONThough potassium salts of rare earth substituted silicotungsticacids were synthesized early in 1971 by R.D.Peacock etc.,sofar the reports about the application of the corresponding acidshave not been found... INTRODUCTIONThough potassium salts of rare earth substituted silicotungsticacids were synthesized early in 1971 by R.D.Peacock etc.,sofar the reports about the application of the corresponding acidshave not been found.We prepared fourteen rare earth substitutedsilicotungstic acids and determined their thermal stability,IRabsorption Spectra and x-ray diffraction spectra.Furthermore,thecatalytic activities of the fourteen heteropoly acids in acid cata-lytic reaction were investigated.Our experimental results demonstrated rare earth substituted silico-tungstic acids have very high catalytic activity in the reaction of 展开更多
关键词 SUIDIES ON SOME PROPERTIES AND catalysis OF RARE EARTH HETEROPOLY ACIDS
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Br?nsted acid catalyzed addition of N^1-p-methyl toluenesulfonyl triazole to olefins for the preparation of N^2-alkyl 1,2,3-triazoles with high N^2-selectivity
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作者 石津玮 朱莉莉 +1 位作者 闻建 陈自立 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第8期1222-1226,共5页
An efficient new method has been developed to synthesize N2‐alkyl 1,2,3‐triazole products by tol‐uenesulfonic acid (TsOH) catalyzed addition of N1‐Ts substituted 1,2,3‐triazoles to olefins. The reac‐tions of m... An efficient new method has been developed to synthesize N2‐alkyl 1,2,3‐triazole products by tol‐uenesulfonic acid (TsOH) catalyzed addition of N1‐Ts substituted 1,2,3‐triazoles to olefins. The reac‐tions of monosubstituted and unsubstituted triazole substrates with various olefins, including vinyl esters, are explored. 展开更多
关键词 Bronsted acid catalysis N2-alkyl 1 2 3-triazole N1-toluenesulfonyl triazole Olefin reaction High N2-selectivity
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Liquid organic hydrogen carriers 被引量:14
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作者 Teng He Qijun Pei Ping Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第5期587-594,共8页
The development of efficient hydrogen storage materials is one of the biggest technical challenges for the coming "hydrogen economy". The liquid organic hydrogen carriers (LOHCs) with high hydrogen contents, rever... The development of efficient hydrogen storage materials is one of the biggest technical challenges for the coming "hydrogen economy". The liquid organic hydrogen carriers (LOHCs) with high hydrogen contents, reversibilities and moderate dehydrogenation kinetics have been considered as an alternative option supplementing the extensively investigated inorganic hydride systems. In this review, LOHCs for long distance H2 transport and for onboard application will be discussed with the focuses of the design and development of LOHCs and their hydrogenation & dehydrogenation catalyses. 展开更多
关键词 Liquid organic hydrogen carrier CycloalkanesHeterocycleFormic acid catalysis
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Zirconium triflate grafted on SBA-15 as a highly efficient solid acid catalyst for ring opening of epoxides by amines and alcohols 被引量:2
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作者 Kamlesh N. Tayade Lianyue Wang +3 位作者 Sensen Shang Wen Dai Manish Mishra Shuang Gao 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第4期758-766,共9页
Metal(Al,Ti,Zr)triflate grafted mesoporous SBA‐15(AlTf/S,TiTf/S,ZrTf/S)samples were synthesizedas inexpensive solid acid materials by a simple one‐pot‐two‐step synthesis methodology.These materials were characteri... Metal(Al,Ti,Zr)triflate grafted mesoporous SBA‐15(AlTf/S,TiTf/S,ZrTf/S)samples were synthesizedas inexpensive solid acid materials by a simple one‐pot‐two‐step synthesis methodology.These materials were characterized by X‐ray diffraction,N2‐sorption,thermogravimetric analysis,Fourier transform infrared spectroscopy(FT‐IR),in‐situ pyridine FT‐IR spectroscopy,and elementalanalysis.ZrTf/S was found to be a highly efficient and reusable solid acid catalyst for ring opening ofepoxides with amines and alcohols and producedβ‐amino alcohols andβ‐alkoxy alcohols respectivelyunder ambient reaction conditions.The ZrTf/S catalyst showed the highest activity,whichwas attributed to its high acidity compared with that of the Ti and Al containing samples. 展开更多
关键词 Epoxide ring opening Acid catalysis Metal triflate Grafted catalyst Mesoporous silica
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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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Selective esterification of glycerol with acetic acid to diacetin using antimony pentoxide as reusable catalyst 被引量:2
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作者 Wenfei Hu Yan Zhang +3 位作者 Yizheng Huang Jiaxi Wang Jin Gao Jie Xu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第5期632-636,共5页
Glycerol can be obtained as a by-product during biodiesel manufacture. It is important to convert glycerol to value-added products. Glycerol esterification with acetic acid is one of the most promising approaches for ... Glycerol can be obtained as a by-product during biodiesel manufacture. It is important to convert glycerol to value-added products. Glycerol esterification with acetic acid is one of the most promising approaches for glycerol utilization. It is usually difficult to obtain diacetin with good activity and selectivity. In this work, glycerol esterification with acetic acid over different metal oxides, such as Bi2O3, Sb2O3, SnO2, TiO2, Nb2O5 and Sb2O5, was investigated. It was found that in the six investigated metal oxides, only Sb205 resulted in good activity and selectivity to diacetin. Under the optimized conditions, the glycerol conversion reached 96.8%, and the selectivity to diacetin reached 54.2%, while the selectivity to monoacetin and triacetin was 33.2% and 12.6%, respectively. The catalysts were characterized with FT-IR spectra of adsorbed pyridine, which indicated that in the six investigated metal oxides, only Sb2O5 possessed Bronsted acid sites strong enough to protonate adsorbed pyridine. The good catalytic activity and selectivity to diacetin might be mainly attributable to the Bronsted acid sites of Sb2O5. Reusability tests showed that with 5b205 as catalyst, after six reaction cycles, no significant change in the glycerol conversion and the selectivity to diacetin was observed. 展开更多
关键词 GlycerolAcetic acid Esterification Diacetin Antimony pentoxide catalysis
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Fabrication of a solid superacid with temperature-regulated silica-isolated biochar nanosheets
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作者 Zengtian Chen Yuxue Xiao +8 位作者 Chao Zhang Zaihui Fu Ting Huang Qingfeng Li Yuanxiong Yao Shutao Xu Xiaoli Pan Wenhao Luo Changzhi Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第4期698-709,共12页
This paper reports a new strategy for the structural reconstruction of biomass carbon sulfonic acid(BCSA)to its solid superacid counterpart.In this approach,a cheap layered biomass carbon(BC)source is chemically exfol... This paper reports a new strategy for the structural reconstruction of biomass carbon sulfonic acid(BCSA)to its solid superacid counterpart.In this approach,a cheap layered biomass carbon(BC)source is chemically exfoliated by cetyltrimethyl ammonium bromide and then converted to silica-isolated carbon nanosheets(CNSs)by a series of conversion steps.The state of the silica-isolated CNSs and the stacking density of their nanoparticles are regulated by the dehydration temperature.Only the highly isolated and non-crosslinked CNSs with loose particle stacking structures obtained upon dehydration at 250℃ can be turned into superacid sites(with stronger acidity than that of 100%H2 SO4)after sulfonation.This is accompanied by the creation of abundant hierarchical slit pores with high external surface area,mainly driven by the strong hydrogen bonding interactions between the introduced sulfonic acid groups.In typical acid-catalyzed esterification,etherification,and hydrolysis reactions,the newly formed superacid exhibits superior catalytic activity and stability compared to those of common BCSA and commercial Amberlyst-15 catalysts,owing to its good structural stability,highly exposed stable superacidic sites,and abundance of mesoporous/macroporous channels with excellent mass transfer rate.This groundbreaking work not only provides a novel strategy for fabricating bio-based solid superacids,but also overcomes the drawbacks of BCSA,i.e.,unsatisfactory structural stability,acidity,and porosity. 展开更多
关键词 Biomass conversion Bio-based sulfonic acid Silica isolation Solid superacid Acid catalysis
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Sulfamic Acid as a Cost-effective Catalyst for Acetolysis of Cyclic Ethers
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作者 WeiZhongGONG BoWANG +3 位作者 YahLongGU LiangYAN LiMingYANG JiShuanSUO 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第6期747-750,共4页
Sulfamic acid has been used as an efficient catalyst and green alternative for conventional acidic materials to promote the acetolysis reaction of THF to produce 1, 4-diacetoxybutane. This method is also applicable in... Sulfamic acid has been used as an efficient catalyst and green alternative for conventional acidic materials to promote the acetolysis reaction of THF to produce 1, 4-diacetoxybutane. This method is also applicable in the acetolysis of other cyclic ethers, such as methyl substituted THF and tetrahydropyran and 1,4-dioxane which is less reactivity. 展开更多
关键词 Sulfamic acid ACETOLYSIS cyclic ether acid catalysis ionic liquid.
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Fabrication of supported acid catalytic composite fibers by a simple and low-cost method and their application on the synthesis of liquid biofuel 5-ethoxymethylfurfural
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作者 Yinhua Yan Huiqin Guo +1 位作者 Kexin Li Liushui Yan 《Green Energy & Environment》 SCIE EI CSCD 2022年第1期165-171,共7页
In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully ... In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully fabricated by a simple method using low-cost raw materials.The characterization results showed that the annealed biomass carbon microspheres derived from waste Camellia oleifera shells were evenly distributed on the polytetrafluoroethylene fibers and the sulfonic groups can be successfully loaded on the surface of annealed biomass carbon microspheres by room temperature sulfonation.Subsequently,the as-prepared A-BCMSs-SO_(3)H@PTFE fibers were applied to the acidcatalyzed synthesis of liquid biofuel 5-ethoxymethylfurfural.The catalytic experiment results indicated that the annealing temperature and time during catalyst preparation have a significant effect on the activity and selectivity of A-BCMSs-SO_(3)H@PTFE fibers.The results of catalytic reaction kinetics showed that the yield of 5-ethoxymethylfurfural can reach more than 60%after 72 h of acid-catalyzed reaction.The stability test showed that the as-prepared A-BCMSs-SO_(3)H@PTFE fibers still maintained a stable acid catalytic activity after four recycles. 展开更多
关键词 Acid catalysis Waste Camellia oleifera shells Sulfonic groups Polytetrafluoroethylene fibers 5-Ethoxymethylfurfural
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Optimization of Biodiesel Production from African Crude Palm Oil (Elaeis guineensis Jacq) with High Concentration of Free Fatty Acids by a Two-Step Transesterification Process
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作者 Francisco Anguebes-Franseschi Atl Córdova-Quiroz +5 位作者 Julia Cerón-Bretón Claudia Aguilar-Ucan Gloria Castillo-Martínez Rosa Cerón-Bretón Alejandro Ruíz-Marín Carlos Montalvo-Romero 《Open Journal of Ecology》 2016年第1期13-21,共9页
In this study, African crude palm olein (CPO) was used to synthesize biodiesel. The objective was to determine the optimal reaction conditions for the methanolysis of olein. The used CPO had a 5.72% concentration of f... In this study, African crude palm olein (CPO) was used to synthesize biodiesel. The objective was to determine the optimal reaction conditions for the methanolysis of olein. The used CPO had a 5.72% concentration of free fatty acids (FFA);thus, the production of biodiesel was carried out in two stages: 1) esterification using sulfuric acid and 2) transesterification using sodium methoxide. In order to optimize the yield of biodiesel during the transesterification process, a central rotatable design and the response surface methodology were used. The studied variables were: catalyst loading, reaction time and reaction temperature. The analysis of variance showed that the variables with significant effect were the catalyst loading, reaction temperature and reaction time;as well as the catalyst loading*reaction temperature and catalyst loading*reaction time. Results indicate that the optimal reaction conditions during transesterification are: 0.65% catalyst loading (wt/wt<sub>aceite</sub>), reaction time of 135 min and a reaction temperature of 56&#176C. The optimal reaction conditions during esterification are: 2.5% weight of catalyst, reaction time of 150 min and a reaction temperature of 64.5&#176C. Under these conditions, a 90% yield of biodiesel was obtained. 展开更多
关键词 Acid catalysis Alkaline catalysis Biodiesel Process Optimization Response Surface Methodology
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Oxidative cyclization of allyl compounds and isocyanide: A facile entry to polysubstituted 2-cyanopyrroles
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作者 Yaping Zhang Wei Zhou +4 位作者 Mingchun Gao Tianqi Liu Bingxin Liu Chang-Hua Ding Bin Xu 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第4期330-335,共6页
A facile Tf OH-catalyzed oxidative cyclization of allyl compounds and isocyanide has been developed with the assistance of DDQ, where isocyanide is used as the crucial "N" and "CN" sources. Highly ... A facile Tf OH-catalyzed oxidative cyclization of allyl compounds and isocyanide has been developed with the assistance of DDQ, where isocyanide is used as the crucial "N" and "CN" sources. Highly functionalized 2-cyanopyrroles are constructed efficiently through a new formal [3 + 2] mode, demonstrating diverse reactivity and synthetic utility in organic chemistry. 2-Cyanopyrrole is converted into a nucleobase analogue of Remdesivir and 5H-pyrrolo[2,1-a]isoindole through a three-step or a two-step sequence, respectively. This protocol features broad substrate scope, operational simplicity and good functional group tolerance. 展开更多
关键词 ISOCYANIDE Cyanopyrrole INSERTION Allyl compound Bronsted acid catalysis
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An unprecedented synthesis of axially chiral biaryls by rearrangement and aromatization of carbocations with central-to-axial conversion of chirality
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作者 Qi Liu Xue-Dong Li +1 位作者 Liang Cheng Li Liu 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第9期2998-3003,共6页
The central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements,which prov... The central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements,which provides efficient methods for the preparation of axially chiral compounds.However,developing catalytic asymmetric approaches for constructing these central chirality precursors and the efficient central-to-axial chirality conversion remains a challenge due to the requirement of aromatization or elimination process.In this work,we have developed an unprecedented enantioselective intramolecular FriedelCrafts alkylation with unactivated-ketone carbonyls from which a chiral tertiary alcohol was generated with high efficiency and excellent enantioselectivity.In addition,the central-to-axial chirality conversion strategy has been successfully applied to the synthesis of enantioenriched biaryls via a less-explored carbocation-initiated rearrangement and aromatization under the promotion of Lewis acid.This methodology provided a straightforward and sustainable access to a broad range of biaryl-2-carboxylic acid and in excellent yields(up to 92%)and excellent central-to-axial chirality conversion(up to 99%conversion percentage).This work could be a great model for developing new methods for synthesizing axially chiral biaryls and a general protocol for the rearrangement and aromatization of carbocations for further functionalization. 展开更多
关键词 br?nsted acid catalysis desymmetrization phosphoric acid axially chiral biaryls central-to-axial conversion
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Organic Brønsted Acid-Catalyzed Stereoselective Cationic RAFT Polymerization:The Effect of RAFT Agents
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作者 Zheng-Yi Zhang Zan Yang +1 位作者 Yun Liao Sai-Hu Liao 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第6期711-717,共7页
The tacticity of vinyl polymers is a key factor affecting the properties of materials.Recently,organic Brønsted acids have been demonstrated as effective catalysts for the development of highly stereoselective ca... The tacticity of vinyl polymers is a key factor affecting the properties of materials.Recently,organic Brønsted acids have been demonstrated as effective catalysts for the development of highly stereoselective cationic reversible addition-fragmentation chain transfer(RAFT)polymerizations of vinyl ethers,in which the use of RAFT agents could allow the control the molecular weight and tacticity of polymer products simultaneously.However,the effect of RAFT agents on the tacticity-regulation remains elusive and lacks of investigation.In this study,we synthesized four types of RAFT agents and evaluated their influence in the stereoselective cationic polymerization of isobutyl vinyl ether in the presence of PADI as a Brønsted acid catalyst,which unveils that the Z group of RAFT agents could not only affect the polydispersity of the products,but also exert a profound effect on the stereoselectivity.After extensive screening of the RAFT agents,high stereoregularity(isotacticity,90%m)was obtained when using dithiocarbonate ester-type RAFT agents with a benzyloxy Z group. 展开更多
关键词 Bronsted acid catalysis Stereoselective cationic polymerization RAFT polymerization Chain transfer agents TACTICITY
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Polyoxometalates-based heterogeneous catalysts in acid catalysis 被引量:1
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作者 Lifei Lian Huaiying Zhang +2 位作者 Sai An Wei Chen Yu-Fei Song 《Science China Chemistry》 SCIE EI CSCD 2021年第7期1117-1130,共14页
Acid catalysis,one of the most important industrial processes,suffers from the toxicity,corrosion and recyclability problems of conventional homogeneous acid catalysts.Thus,the development of green heterogeneous acid ... Acid catalysis,one of the most important industrial processes,suffers from the toxicity,corrosion and recyclability problems of conventional homogeneous acid catalysts.Thus,the development of green heterogeneous acid catalysts becomes the focus of fundamental research and industrial catalysis.As a class of discrete anionic metal-oxygen clusters with tunable structure at the molecular and atomic scales,polyoxometalates(POMs)benefit from their super strong Br?nsted acidity,high proton mobility,and thermal stability.POMs-based heterogeneous catalysts have been used as the potential green alternatives to conventional homogeneous acid catalysts.In this review,we summarize recent progress on the design strategies of the POMs-based heterogeneous catalysts and their catalytic properties in acid-catalyzed reactions,where they are combined with functionalized cations,modified through covalent interactions,supported onto the non-precious metal support,and introduced into the framework of porous polymers.The design,functional strategies and catalytic performance of these POMs-based heterogeneous catalysts in specific acid-catalyzed reactions are emphasized. 展开更多
关键词 POLYOXOMETALATES solid acid catalyst acid catalysis heterogeneous catalysis ESTERIFICATION
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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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Recent advances in polyoxometalates acid-catalyzed organic reactions 被引量:1
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作者 Yu-Feng Liu Chang-Wen Hu Guo-Ping Yang 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第5期143-154,共12页
Polyoxometalates(POMs)have conducive properties such as controlled Bronsted and Lewis acidity,high thermal stability,nontoxic nature,tunable solubility,and less corrosiveness.POMs have been extensively applied in cata... Polyoxometalates(POMs)have conducive properties such as controlled Bronsted and Lewis acidity,high thermal stability,nontoxic nature,tunable solubility,and less corrosiveness.POMs have been extensively applied in catalytic organic reactions and have an exciting prospect for industrial applications.This review summarized recent progress in the application of POMs as acid catalysts for various organic reactions including C-C bond formation,C-N bond formation,C-O bond formation,heterocyclic synthesis reactions,cyanosilylation and hydrolysis reactions.Various POMs catalysts including heteropoly acids(HPAs)and cationic functionalized HPAs with Bronsted acidity,HPAs supported on non-precious metal support with Bronsted acidity(or both Bronsted and Lewis acidity),transition metal substituted POMs with Lewis acidity were applied in above reactions.This review attempts to provide up-to-date information about POMs acid-catalyzed organic reactions and propose future prospects. 展开更多
关键词 POLYOXOMETALATES Acid catalysis C-C bond formation C-N bond formation C-O bond formation Heterocyclic synthesis Cyanosilylation and hydrolysis reactions
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Br■nsted acid-catalyzed asymmetric dearomatization of indolyl ynamides: Practical and enantioselective synthesis of polycyclic indolines
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作者 Zhi-Xin Zhang Xuan Wang +3 位作者 Jia-Tian Jiang Jie Chen Xin-Qi Zhu Long-Wu Ye 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第3期317-321,共5页
Catalytic asymmetric dearomatization of indoles and alkynes has received much attention in the past decade because this strategy offers an attractive and alternative way for the efficient synthesis of valuable chiral ... Catalytic asymmetric dearomatization of indoles and alkynes has received much attention in the past decade because this strategy offers an attractive and alternative way for the efficient synthesis of valuable chiral polycyclic indolines. However, these reactions have been mostly limited to transition-metal catalysts, and the related chiral Br■nsted acid catalysis has been scarcely reported. Herein, we disclose a chiral phosphoric acid-catalyzed asymmetric dearomatization of indolyl ynamides by direct activation of alkynes. This metal-free method enables the practical and atom-economical construction of an array of valuable chiral polycyclic indolines in moderate to good yields with high enantioselectivities. 展开更多
关键词 Br■nsted acid catalysis DEAROMATIZATION HETEROCYCLES YNAMIDES STEREOSELECTIVITY
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A Lewis acid-catalyzed tandem reaction enabling 2-arylglycerol derivative as a versatile 1,3-biselectrophile for the synthesis of 4H-chromenes and 2-pyridinones
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作者 Shaomin Chen Tianjian Zhang +3 位作者 Zhenhua Xu Bo You Minghao Li Yanlong Gu 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第9期147-150,共4页
Acid-catalyzed tandem reactions were established by employing a novel class of 2-arylglycerol derivative,5-aryl-1,3-dioxan-5-ol,as versatile 1,3-biselectrophile.In the reactions,5-aryl-1,3-dioxan-5-ol works like atrop... Acid-catalyzed tandem reactions were established by employing a novel class of 2-arylglycerol derivative,5-aryl-1,3-dioxan-5-ol,as versatile 1,3-biselectrophile.In the reactions,5-aryl-1,3-dioxan-5-ol works like atropaldehydes or 2-aryl malondialdehydes,and can react with 2-naphthols andβ-keto amides,allowing the synthesis of 4H-chromenes and 5-aryl-2-pyridinones.High yields,good functional group tolerance,broad substrate scope and simple reaction operation make this protocol attractive. 展开更多
关键词 Lewis acid catalysis 2-Arylglycerol derivative 1 3-Biselectrophile Six-membered heterocycles [3+3]cyclization
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