Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Chunlai Liu,Na Wang,Zelin Meng,Mingyang Song,Heming Zhao,Jianglei Hu,Fengwei Shi
The Knoevenagel reaction is one of the most significant reactions in the industrial synthesis of organic materials, pharmaceuticals, and biological compounds. In this study, 2-cyanoethyltriethoxysilane (CTES) was employed as a functionalizing agent to prepare carboxyl-functionalized silica (SBA-16-Cx) using a one-pot method. Subsequently, carboxyl groups served as anchoring points for Cr³⁺, and MOFs-modified SBA-16 (SBA-16-Cx@MIL) was obtained by in situ synthesis. The resulting materials were characterized using FT-IR, XPS, XRD, N 2 adsorption-desorption analysis, SEM, TEM, 13 C MAS NMR, and TG, which confirmed the successful synthesis of MIL-101 on the support. Meanwhile, the pore size of the composite was reduced from 5.1 nm (SBA-16) to 0.6 nm (SBA-16-C1.0@MIL). The condensation reaction of benzaldehyde with malononitrile was selected as a model reaction. The effects of various factors, including solvents, reactants molar ratios, temperature, catalyst dosage, and reaction time, on the reaction were studied. Under optimized conditions, the conversion rate of benzaldehyde reached 100 % and the catalyst demonstrated excellent stability for repeated use. The reaction follows second-order kinetics (R 2 >0.99), and the activation energy of the reaction was 17.18 kJ/mol. Finally, the mechanism of the catalytic process was proposed. This work provides a green catalytic route for the synthesis of α,β-unsaturated carbonyl compounds.
研究领域:
材料科学
·
催化化学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2021
·Vol. 12
·期 1
·87-93
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IF 4.987
Wang Yun,Yao Qiao-Xia,He Jia-Rui,Liang Zhi-Hui,Li Xiang,Cheng Hong,Li Li-Ling
Knoevenagel condensation of acetylacetone and aromatic aldehyde catalyzed by L-proline in the choline chloride-based deep eutectic solvents was achieved. High yields are up to 96.6%. Mild reaction conditions, enhanced rates, improved yields, recyclability of deep eutectic solvents containing L-proline, and reagents’ reactivity which is different from that in standard organic solvents are the remarkable features observed in deep eutectic solvents. The deep eutectic solvents containing catalyst was recycled in four subsequent runs with no decrease in activity.
研究领域:
有机化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 131
·期 19
·
IF 1.64
Huachuan Zhang,Min Li,Yuyuan Deng,Chengxi Zhang,Qichao Ran,Yi Gu
In this article, a kind of styrylpyridine-containing polybenzoxazine was obtained via the Knoevenagel reaction between benzaldehyde and methylpyridine groups. The benzoxazine monomer (MPBC) containing the benzaldehyde and methylpyridine groups was synthesized firstly and its structure was characterized by Fourier transform infrared (FTIR) spectra, 1 H NMR and 13 C NMR. With the aid of differential scanning calorimetry, FTIR, and photoluminescent tests, the interesting curing behaviors were probed. The results showed that the ring-opening polymerization occurred at lower temperature, and the Knoevenagel reaction further took place at elevated temperature. The amine and phenol moieties were bonded together to form the styrylpyridine structure. Due to these special crosslinking structures, the corresponding polybenzoxazine exhibited excellent thermal stability, and had a special high char yield of 74.5%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40823.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2023
·
IF 3.8
Peng Xiong,Tong-Wei Zhang,Shi-Ming Li,Mei-Yu Xu,Guang-Ming -Liang,Liu-Cheng Gui,Xiu-Jian Wang
Two tetranuclear copper cages with tubular type, [Cu 4 (BMBA) 4 ((CH 3 ) 2 N) 2 (H 2 O) 2 ] ( 1 ) and [Cu 4 (BMBA) 4 (Bipy)(H 2 O) 2 ] ( 2 ), were successfully constructed by the reaction of Cu(NO 3 ) 2 with dicarboxylic acid 4,4′-[( ethylazanediyl ) bis ( methylene )]-bis[(1,1′-biphenyl)-2-carboxylic acid] (H 2 BMBA) under solvothermal conditions. The complexes 1 and 2 exhibit a similar cage structure, formed by four ligands connecting two binuclear copper paddle-wheel secondary building units (SBUs). Interestingly, the complex 2 was obtained by appropriately binding of 4, 4′-bipyridine (Bipy) molecule on the axial positions of two Cu paddle-wheels inside the cage. For this reason, the complex 2 exhibits excellent stability in some common organic solvents at room temperature and aqueous solutions with a pH of 2 to 12. Upon thermal activation of complex 2 , the coordinated water molecules can be removed, and its exposed metal active-sites show Lewis acid character, which can be used an efficient heterogeneous catalysis of Knoevenagel condensation (C C) and Clauson-Kaas (C N) reactions.
研究领域:
化学
·
材料科学
·
催化反应
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Xiaoqing Yuan,Ju Liu,Yanlei Wang,Xingming Jie,Jingyu Qin,Hongyan He
Knoevenagel condensation reaction is important for generating C C double bonds and providing various valuable intermediates in organic chemistry, which always need harsh conditions including high reaction temperature, difficult catalyst recovery, difficult product separation, etc. In this work, a novel class of dual-responsive emulsion reactor was prepared for the Knoevenagel condensation reaction between malononitrile and aromatic aldehyde, where the temperature and CO 2 -responsive ionic liquids (ILs) were used as an emulsifier, responder, and catalyst simultaneously. Driven by temperature or CO 2 , the emulsion reactor undergoes reversible and controllable transformations between emulsification and demulsification, where efficient catalytic reactions, product separation, and reactor recovery are all achieved. The isolated product yield of 2-(4-chlorobenzylidene)-malononitrile remained above 90% after 5 cycles of the emulsion reactor. NMR and molecular dynamics simulations showed that the temperature drives the reversible stretching and curling of the polyether chain on the cation, while CO 2 reacts with the –COO - group on the anion to form carbonates and carboxylic acids in water, leading to changes in the surface activity of ILs, thereby reversibly regulating the demulsification and emulsification of the emulsion. Hence, through the dual stimuli-responsive ILs, the efficient reaction can be performed in the homogeneous phase, and the products and catalysts can be easily separated in the heterogeneous phase. These results on the revisable microreactor can not only help to design the smart and efficient “homogeneous reaction-heterogeneous separation” systems but also support the development of green sustainable chemistry.
研究领域:
有机化学
·
绿色化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2015
·
IF 0.633
Fang-Ming Wang,Dan Bao,Bing-Xiang Hu,Ze-Yu Zhou,Deng-Deng Huang,Li-Zhuang Chen,Yuan-Yuan Dan
A series of novel 10-substituted 3,6-diphenyl-9-aryl-3,4,6,7,9,10-hexahydroacridine-1,8(2H,5H)-dione derivatives synthesised by condensation of different amines with xanthenes, was prepared from 5-phenylcyclohexane-1,3-dione and aromatic aldehydes by a Knoevenagel and Michael reaction and cyclisation catalysed by a trace of l-proline at room temperature. In addition, the molecular structure of a xanthene was determined by single-crystal X-ray diffraction analysis.
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2018
·
IF 3.972
Pengfang Zhang,Yun Xiao,Hui Sun,Xiaoping Dai,Xin Zhang,Haixia Su,Yuchen Qin,Daowei Gao,Axiang Jin,Hai Wang,Xiubing Wang,Shigang Sun
Morphology-controlled synthesis of metal–organic frameworks (MOFs) is of tremendous importance to understand the morphology–structure–property relationships. Although great emphasis has been placed on the controllable synthesis of MOFs, the preparation of hollow and nanoframe-like MOFs, especially using the microwave irradiation method, remains a great challenge. In the present work, we report microwave-assisted synthesis of hollow butterfly and ring zeolitic imidazolate framework-8 (ZIF-8) with the stimuli of Ni ions. Interestingly, the sphere, butterfly, and fiber ZIF-8 catalysts were also fabricated when adjusting the weight ratio of Zn and Ni resources. Specifically, sphere, butterfly, hollow butterfly, and ring particles have maintained the ZIF-8 structure. On the basis of the time sequential experiments, we inferred that the formation of hollow butterfly and ring particles is driven by the change of surface energy. The Knoevenagel reaction was carried out to explore the catalytic activity of these ZIF materials. The ring particles with ZIF-8 structure showed the highest catalytic activity. The open structure, thin walls, and the amount of basicity have been extensively discussed to shed light on the superior catalytic performance of ring particles.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jialin Yang,Jierui Wang,Qi Zhang,He Zhu,Shiping Zhu
The synthesis of monolithic MOF aerogel is a critical step in applying MOFs to many practical applications. MAF-6 (RHO-[Zn(eim) 2 ], Heim = 2-ethylimidazole) is a type of MOF materials with large cavities and apertures. However, it has been much less studied due to the difficulty in obtaining it via conventional synthesis protocols. Herein, a nearly pure MAF-6 monolith with macro/meso/microporous pore structure is synthesized in situ by emulsion template method, which exhibits hierarchical structure with high porosity (∼80 %), large specific surface area (up to 1135 m 2 /g), and excellent mechanical properties. In addition, the monoliths demonstrate excellent capability and stability to separate methanol/ethanol mixtures and high catalytic performance in the Knoevenagel reaction. This work provides an effective approach to prepare MAF-6 monoliths for potential application in catalysis, adsorption, separation, etc.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2018
·
IF 4.513
Bin Xie,Yingjie Xu,Xiaochen Tang,Hegang Shu,Tingting Chen,Xiao Zhu
The design of acidity and alkalinity is an important characteristic of ionic liquids , and it also affects their application. For this reason, the alkalinity of six hydroxypyridine anion-based protic ionic liquids (PILs) was determined by potentiometric titration , and the effect of the type of cation and the position of nitrogen atom of anion on the alkalinity was discussed. Furthermore, six hydroxypyridine anion-based PILs were used as catalysts for Knoevenagel reaction , and the relationship between the catalytic performance and the alkalinity was investigated. The results indicate that the type of cation has little effect on the alkalinity of the studied PILs, while the position of nitrogen atom of anion has a significant influence on the alkalinity, and the order of the alkalinity is as follows: [2‑Op] − > [4‑Op] − > [3‑Op] − , resulting from the positive cooperative interaction between electronegative nitrogen and oxygen atoms, which is confirmed by DFT calculation . Consequently, the PILs with [2‑Op] − anion showing stronger alkalinity exhibits better catalytic performance for Knoevenagel reaction.
研究领域:
化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2014
·Vol. 12
·期 21
·3493-3498
·
IF 3.487
Yaping Zhao,Lu Sun,Tieqiang Zeng,Jiayi Wang,Yanqing Peng,Gonghua Song
Copper-catalyzed direct olefination of benzaldehydes into 1,3-diarylpropenes by a novel domino Knoevenagel-decarboxylation-Csp3-H activation sequence is reported. This method provides a concise and effective route toward the synthesis of unsymmetrical 1,3-diarylpropene derivatives.
研究领域:
有机化学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Boya Qiu,Senqing Fan,Yilin Wang,Jiaojiao Chen,Zeyi Xiao,Yuyang Wang,Yu Chen,Jingyun Liu,Yangmei Qin,Shizhao Jian
A novel catalytic membrane micro-reactor (CMMR) is assembled with ZIF-8 in situ immobilized in polyethersulfone (PES) membrane pores. In this structure, ZIF-8 is evenly distributed on pore walls throughout membrane thickness. The size of ZIF-8 particles is lower than 50 nm. Loading of ZIF-8 can be achieved in the range of 10–180%. This CMMR exhibits high catalytic performance during the Knoevenagel reaction of Benzaldehyde and Ethyl cyanoacetate. The apparent reaction rate constant can be increased by 140.9% at 20 °C, catalyzed by the CMMR than that by ZIF-8 powders under batch catalysis mode. The apparent reaction rate constant can be increased further by 35.9%, with the value being 0.072 ± 0.006 min −1 , if plug-flow reaction mode is adopted. High catalytic stability can be achieved, and this CMMR can be recycled and reused over 10 repeating cycles and 300 min without significant decrease in the conversion rate. The conversion rate is 99.5 ± 0.2% at 80 °C, with loading of ZIF-8 being 85% and the membrane flux being 960 mL m −2 h −1 . Increasing loading of ZIF-8 and temperature can both improve the conversion rate and the apparent reaction rate constant. The apparent activation energy is halved catalyzed by the CMMR than that by ZIF-8 powders.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 13
·4508-4517
·
IF 4.099
Hang Huo,Xianzhu Xu,Tingting Zhao,Yudong Li,Yanqiu Jiang,Kaifeng Lin
Hybrid molecularly imprinted mesoporous silicas were synthesized by co-condensation of tetraethoxysilane and functional organosilica precursors of HQP and BPAP, in which hydroquinone (HQ) and bisphenol A (BPA) were linked as imprinting molecules. Owing to the existence of a thermally reversible covalent bond of carbamate (–NH–COO–), the imprinting molecules could be eliminated under thermal treatment and molecularly imprinted cavities were formed in the framework wall. All of these materials were used to catalyze heterogeneous Knoevenagel reactions and proved to exhibit higher catalytic conversion and turnover frequency (TOF) number compared with the materials with imprinting molecules, which is attributed to the presence of amino groups with higher basicity and molecularly imprinted cavities. Importantly, compared with amino functionalized SBA-15 materials, the decisive role of molecularly imprinted cavities in the enhanced accessibility of amino groups in a mesoporous framework was further confirmed. Moreover, the size of imprinting molecules has an influence on the catalytic conversion and TOF values: imprinting molecules with relatively bulkier size tend to provide higher accessibility to the active sites. The amino groups in the framework are extremely stable during the reaction procedure and recycling process.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）