- Synthesis of KOH/SnO2 solid superbases for catalytic Knoevenagel condensation
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KOH/SnO2 solid superbases of specific morphology and uniform pore structure were synthesized. The SnO2 support was prepared by reflux digestion using graphene oxide as template and employed for the loading of KOH by means of grinding
- Xie, Jun,Chen, Lang,Au, Chak-Tong,Yin, Shuang-Feng
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- Efficient Synthesis of Branched Polyamine Based Thermally Stable Heterogeneous Catalyst for Knoevenagel Condensation at Room Temperature
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Abstract: In this paper, a new convenient strategy for the synthesis of polyethylenimine functionalized Si-MCM-41 grafted on surface modified graphene oxide has been developed. The as-synthesised catalyst exerts good catalytic activity and reusability tow
- Chaudhuri, Haribandhu,Gupta, Radha,Dash, Subhajit
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- Mesoporous carbon nitride as a metal-free base catalyst in the microwave assisted Knoevenagel condensation of ethylcyanoacetate with aromatic aldehydes
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High nitrogen containing mesoporous carbon nitride (MCN) was synthesized and investigated as a metal-free base catalyst for the Knoevenagel condensation of ethylcyanoacetate with aromatic aldehydes. The catalyst was found to be efficient for the Knoevenag
- Ansari, Mohd Bismillah,Jin, Hailian,Parvin, Mst. Nargis,Park, Sang-Eon
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- Synthesis, characterization and heterogeneous base catalysis of amino functionalized lanthanide metal-organic frameworks
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Lanthanide metal-organic frameworks (Ln-MOFs) are featured by their tolerance to water and dense structure. In this work, an amine-functionalized Ln-MOF was facilely synthesized by coordination of terbium with 2-aminoterephthalic acid under the condition of microwave irradiation. The crystal structure was characterized by single crystal X-ray diffraction, FT-IR, Raman, TG-DTA and XPS analysis. The basic catalytic activity of the NH2-Tb-MOF was evaluated for Knoevenagel condensation and Henry reactions. Apart from the high activity and 100% selectivity to the condensation product, the NH2-Tb-MOF catalyst could be easily recycled and reused owing to the high stability of the MOF framework formed by coordination of Tb3+ with carboxylic groups. Remarkably, the NH2-Tb-MOF exhibited size-selective catalysis to substrates. For the small-sized reactants, it displayed comparable activity to the homogeneous catalyst of aniline owing to the high dispersion of NH2? active sites and the low diffusion limits. However, in the same reaction system, extremely poor activity in Knoevenagel condensation and Henry reaction for the bulky substrate 4-(tert-butyl) benzaldehyde was observed due to the both effects of substitute and inhibition of diffusion into the micropores. Crystal structure analysis provided a mechanistic evidence that the heterogeneous base catalysis arose from the amino groups densely distributed inside the micropores.
- Huang, Jinping,Li, Chunmei,Tao, Lingling,Zhu, Huilin,Hu, Gang
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- Polystyrene-supported chloroaluminate ionic liquid as a new heterogeneous Lewis acid catalyst for Knoevenagel condensation
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Non-hygroscopic polystyrene-supported chloroaluminate ionic liquid was prepared from the reaction of Merrifield resin with 1-methylimidazole followed by reaction with aluminum chloride. This Lewis acidic ionic liquid is environmentally friendly heterogene
- Parvanak Boroujeni, Kaveh,Jafarinasab, Mina
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- Microwave enhanced Knoevenagel condensation of ethyl cyanoacetate with aldehydes
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The reaction rate of Knoevenagel condensation can be dramatically enhanced by irradiating the reaction mixture containing ethyl cyanoacetate, an aldehyde, P2O5, piperidine, and chlorobenzene with a commercial microwave oven. A number of Knoevenagel condensation products were prepared in good yields in very short reaction times (2-15 min) under the microwave irradiation.
- Kim, Sang-Yun,Kwon, Pan-Suk,Kwon, Tae-Woo,Chung, Sung-Kee,Chang, Young-Tae
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- Amino-functionalized mesostructured cellular foam silica: A highly efficient and recyclable catalyst in the Knoevenagel condensation reaction
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Mesostructured cellular foam silica was functionalized by an amino group (MCF-NH2) using the postsynthesis grafting method and utilized as a recyclable catalyst for the Knoevenagel reaction to afford α, β-unsaturated compounds. The catalyst was systematic
- Dong, Hao,Yang, Hongyuan,Zhang, Tengfei,Liu, Qing
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- Tailoring a magnetically separable NiFe2O4nanoparticle catalyst for Knoevenagel condensation
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A magnetically separable NiFe2O4nanoparticle catalyst was prepared readily via a simple one-step hydrothermal process. The catalytic performance of this hetero-nanostructure was investigated by Kneovenagel condensation with aldehydes
- Li, Qichen,Wang, Xiaozhong,Yu, Yanyun,Chen, Yingqi,Dai, Liyan
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- MOFs assembled from C 3symmetric ligands: Structure, iodine capture and role as bifunctional catalysts towards the oxidation-Knoevenagel cascade reaction
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Three new NiII/CoII-metal organic frameworks were self-assembled by the reaction of C3 symmetric 1,3,5-tribenzoic acid (H3BTC) and 2,4,6-tris(4-pyridyl)-1,3,5-triazine (4-TPT) ligands and NiII/CoII salts under solvothermal conditions. Isomorphous MOF1 and MOF2 exhibit a 3D pillar-layer framework based on binuclear M2(OH)(COO)2 units connected by tritopic BTC3- and 4-TPT ligands with a novel (3,5)-connected topology net. MOF3 displays a 3-fold interpenetrated 3D network exhibiting a (3,4)-connected topology net. The porous MOF3 can reversibly take up I2. The activated MOFs contain both Lewis acid (NiII center) and basic (uncoordinated pyridyl or carboxylic groups) sites, and act as bifunctional acid-base catalysts. The catalytic measurements demonstrate that the activated MOF3 exhibits good activities for benzyl alcohol oxidation and the Knoevenagel reaction and can be recycled and reused for at least four cycles without losing its structural integrity and high catalytic activity. Thus, the catalytic properties for the oxidation-Knoevenagel cascade reaction have also been studied.
- Zhang, Ying-Ying,Liu, Qing,Zhang, Lin-Yan,Bao, Yu-Mei,Tan, Jing-Yi,Zhang, Na,Zhang, Jian-Yong,Liu, Zhen-Jiang
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- A Simple and Highly Versatile Procedure for the Knoevenagel Condensation Promoted by an Efficient, Eco-Friendly, and Recyclable nano-ZnO Catalyst
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Abstract: A simple, highly versatile, and efficient protocol for the synthesis of substituted olefins from various aromatic aldehydes and active methylene compounds by Knoevenagel condensation using an efficient, eco-friendly, and recyclable nano-ZnO cata
- Alam, M. M.,Asiri, Ya. I.,Sulthana, S. Sh.,Tasqeeruddin, S.
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- Calcined Dolomite: An Efficient and Recyclable Catalyst for Synthesis of Α, Β-Unsaturated Carbonyl Compounds
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Abstract: Calcined dolomite was utilized as a low-cost and efficient catalyst for the Knoevenagel condensation of aldehydes with active methylene compounds such as malononitrile and ethyl cyanoacetate to afford substituted α, β-unsaturated carbonyl compou
- Yang, Hongyuan,Dong, Hao,Zhang, Tengfei,Zhang, Qi,Zhang, Guangwei,Wang, Peng,Liu, Qing
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- 3-Aminopropyl-triethoxysilane Functionalized Graphene Oxide: A Highly Efficient and Recyclable Catalyst for Knoevenagel Condensation
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A solid base catalyst has been prepared by covalent functionalization of graphene oxide with 3-aminopropyl-triethoxysilane. The catalyst exhibits a superior catalytic performance in Knoevenagel condensation (over 90 % yield and at least seven times reusab
- Huang, Jie,Ding, Shunmin,Xiao, Weiming,Peng, Yadan,Deng, Shengjun,Zhang, Ning
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- Synthesis, characterization and application of α-Ca3 (PO4)2 as a heterogeneous catalyst for the synthesis of 2.3-diphenylquinoxaline derivatives and knoevenagel condensation under green conditions
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Green chemistry is now paramount in modern life and industrial sector. It has become a research priority and a scientific challenge. In this study, alpha-tricalcic phosphate was prepared as a green catalytic medium. This medium has been characterized by v
- Anahmadi, Haddou,Benzekri, Zakaria,Boukhris, Said,El hajri, Fatima,El youbi, Mohamed Salahdine,Fathi, Majda,Idrissi, Brahim Chafik El,Sibous, Sarra,Souizi, Abdelaziz
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- Synthesis, characterization, and in vitro antibacterial activity of some new pyridinone and pyrazole derivatives with some in silico ADME and molecular modeling study
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A new series of pyridine-2-one and pyrazole derivatives were designed and synthesized based on cyanoacrylamide derivatives containing 2,4-dichlro aniline and 6-methyl 2-amino pyridine as an aryl group. Condensation of cyanoacrylamide derivatives 3a–d with different active methylene (malononitrile, ethyl cyanoacetate cyanoacetamide, and ethyl acetoacetate) in the presence of piperidine as basic catalyst afforded the corresponding pyridinone derivatives 4a–c, 5, 9, and 13. Furthermore, the reaction of cyanoacrylamide derivatives 3a–d with bi-nucleophile as hydrazine hydrate and thiosemicarbazide afforded the corresponding pyrazole derivatives 14a,b and 16. The newly designed derivatives were confirmed and established based on the elemental analysis and spectra data (IR, 1H NMR, 13C NMR, and mass). The in vitro antibacterial activity was evaluated against four bacterial strains with weak to good antibacterial activity. Moreover, the results indicated that the most active derivatives 3a, 4a, 4b, 9, and 16 might lead to antibacterial agents, especially against B. subtilis and P. vulgaris. The DFT calculations were performed to estimate its geometric structure and electronic properties. In addition, the most active pyridinone and pyrazole derivatives were further evaluated for in silico physicochemical, drug-likeness, and toxicity prediction. These derivatives obeyed all Lipinski’s and Veber’s rules without any violation and displayed non-immunotoxin, non-mutagenic, and non-cytotoxic. Molecular docking simulation was performed inside the active site of Topoisomerase IV (PDB:3FV5). It displayed binding energy ranging from -14.97?kcal/mol to -18.86?kcal/mol with hydrogen bonding and arene–cation interaction. Therefore, these derivatives were suggested to be good antibacterial agents via topoisomerase IV inhibitor. Graphical abstract: [Figure not available: see fulltext.]
- Elhagali, Gameel A. M.,Mahmoud, N. A.,Ragab, Ahmed,Saadon, Khadija E.,Taha, Nadia M. H.
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- Highly Active Copper(I)-Chalcogenone Catalyzed Knoevenagel Condensation Reaction Using Various Aldehydes and Active Methylene Compounds
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First copper(I) chalcogenones catalysed Knoevenagel Condensation reactions have been reported. No illustration of the utilization of this copper-chalcogenone complex class in Knoevenagel Condensation catalysis can be found. Thus, copper(I) bis(benzimidazole-2-chalcogenone) catalysts [Cu(L1)4]+BF4? (1) and [Cu(L2)4]+BF4? (2) (L1 = bis(1-isopropyl-benzimidazole-2-selone)-3-ethyl; L2 = bis(1-isopropyl-benzimidazole-2-thione)-3-ethyl) have been utilized as catalysts in the Knoevenagel Condensation reactions. These copper(I) chalcogenone catalysts have shown high efficiency for the catalytic Knoevenagel Condensation of aryl aldehydes and active methylene compounds. In particular, complex 2, exhibit the best catalytic activities. The scope of the catalytic reactions has been investigated with 22 different molecules. The excellent catalytic activity has been depicted for various types of substrates with either electron-rich or deficient aryl aldehydes. The present investigation features relatively mild reaction conditions with good functional group tolerance and excellent yields. Graphic Abstract: The first copper(I)-chalcogenone complexes catalysed Knoevenagel Condensation reactions?have also been investigated, and revealed the best catalytic activities. [Figure not available: see fulltext.]
- Mannarsamy, Maruthupandi,Prabusankar, Ganesan
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- Bis [hydrazinium (1+)] hexafluoridosilicate:(N2H5)2SiF6 novel hybrid crystal as an efficient, reusable and environmentally friendly heterogeneous catalyst for Knoevenagel condensation and synthesis of biscoumari
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A simple, effective, green and nontoxic protocol was used for the Knoevenagel condensation and the biscoumarin derivatives synthesis. It have demonstrated that the use of a new hybrid crystal as a heterogeneous catalyst makes it possible to obtain several
- El hajri, Fatima,Benzekri, Zakaria,Sibous, Sarra,Ouasri, Ali,Boukhris, Said,Hassikou, Amina,Rhandour, Ali,Souizi, Abdelaziz
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- Organophosphonate-Functionalized Telluromolybdate Containing a [TeMo10O37]10-Building Block and Its Catalytic Efficiency for Knoevenagel Condensation
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A novel organodiphosphonate-based telluromolybdate cluster, (NH4)6Na3H13[TeMo10O37(CoMo2O6L)4]·11H2O [1; L = (O3P)2C(O)(CH2)3NH2], has been successfully synthesized by a simple one-pot aqueous reaction. Intriguingly, the [TeMo10O37]10- subunit with tetrah
- Kong, Hui,Xu, Baijie,Zhen, Jing,Liu, Siyu,Li, Keli,Ma, Pengtao,Wang, Jingping,Niu, Jingyang
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p. 14872 - 14879
(2021/10/01)
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- Ammonium chloride: An efficient and environmentally benign catalyst for knoevenagel condensation of carbonyl and active methylene compounds
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In the present study, a rapid, simple and an efficient procedure for the Knoevenagel condensation of various carbonyl and active methylene compounds in ethanol at a moderate temperature in the presence of a catalytic amount of an efficient, environmentall
- Tasqeeruddin,Asiri, Yahya I.,Mujahid Alam
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p. 3024 - 3028
(2021/01/06)
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- Synthesis and Characterization of a Crown-Shaped 36-Molybdate Cluster and Application in Catalyzing Knoevenagel Condensation
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A novel crown-shaped 36-molybdate cluster with organophosphonate-functionalized polyoxomolybdates, (NH4)17Na7H12[Co(H2O)TeMo6O21{N(CH2PO3)3}]6·42H2O, has been successfully synthesized and well-characterized. It owns the highest nuclearity in the family of organophosphonate-based polyoxometalates reported so far. Furthermore, for the first time in the field, we illustrated that polyoxomolybdate could work as an effective heterogeneous catalyst for the Knoevenagel condensation reaction with high TOF (7714 h-1) and good recyclability. Impressively, the catalytic performance of 1 was also tested successfully in a large scale (~10 g) reaction, where 89percent of reaction yield and 3216 of TON were afforded.
- He, Peipei,Kannan, Thirumurthy,Kong, Hui,Ma, Pengtao,Niu, Jingyang,Wang, Jiawei,Wang, Jingping,Xu, Baijie,Xu, Qiaofei
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- Mechanically fabricated Metal–organic framework/resin composite nanoparticles for efficient basic catalysis
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Zeolitic imidazolate framework-8 (ZIF-8) was successfully composited with an anionic basic resin 201?×?7 (717-resin) to provide a novel ZIF-8/717-resin composite. Its catalytic activity toward the Knoevenagel condensation reaction was evaluated. Results s
- Zhang, Zhi-Hui,Qian, Bing-Bing,Sheng, Pan-Pan,Yang, Sen,Huang, Xian-Feng,Wang, Jin-Long,Chen, Qun,Wang, Liang,He, Ming-Yang
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- Prolinamide functionalized polyacrylonitrile fiber with tunable linker length and surface microenvironment as efficient catalyst for Knoevenagel condensation and related multicomponent tandem reactions
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A series of new prolinamide polyacrylonitrile fiber catalysts with tunable length of alkyl linker and different linker group were prepared by covalent bonding for the first time and well characterized by mechanical strength, FT-IR, XRD, EA, TGA, SEM and water contact angel. The catalytic activities of these fiber catalysts were evaluated in Knoevenagel condensation and one-pot Knoevenagel-Michael multicomponent tandem reactions to synthesize α, β-unsaturated nitrile and 2-amino-4H-chromene derivatives in water. The result show that the suitable linker length attaching amines to fiber matrix as well as the constructed hydrophobic microenvironment by linker group within the surface layers of fiber materials effectively promotes the reactions. In addition, the good swollen capacity of fiber in solvent ensure that the reaction proceed well. Fiber catalyst PANPA?2F modified by prolinamide with a C2 alkyl chain exhibited the best catalytic performance and can be easily recovered and reused for at least ten consecutive cycles without significant loss of catalytic activity and active sites leaching.
- Zhu, Hai,Xu, Gang,Du, Huimin,Zhang, Chenlu,Ma, Ning,Zhang, Wenqin
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p. 217 - 229
(2019/05/16)
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- Precise Control of the Oriented Layered Double Hydroxide Nanosheets Growth on Graphene Oxides Leading to Efficient Catalysts for Cascade Reactions
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In recent years, great attention has been paid to cascade reactions, which can improve efficiency and reduce waste production by implementing several consecutive reactions. Herein, two bifunctional catalysts were successfully prepared by precise control of the oriented layered double hydroxides (LDHs) growth on graphene oxides (GO) using a single-drop and co-precipitation method, respectively. The resultant Ru/LDH-GO-P and Ru/LDH-GO-V composites were characterized by EXAFS, FT-IR, XRD, TG-DTA, BET, XPS, TEM, CO2-TPD, O2-TPD, etc. The catalytic performance of Ru/LDH-GO-P and Ru/LDH-GO-V for one-pot oxidation-Knoevenagel condensation reaction showed significant difference under the same experimental conditions, in which the Ru/LDH-GO-P showed 99 % conversion and 99 % selectivity, in marked contrast of 60.7 % conversion and 47.9 % selectivity using Ru/LDH-GO-V as catalyst. The large enhancement of the catalytic performance using Ru/LDH-GO-P can be attributed to the following reasons: 1) the Co3+ centers in Ru/LDH-GO-P can promote the formation of surface oxygen vacancies that can adsorb and activate O2 to get better performance; 2) the Ru/LDH-GO-P exhibited larger BET surface and more medium-strong basic active sites than the Ru/LDH-GO-V. Moreover, the Ru/LDH-GO-P catalyst can be easily recovered from the reaction system and reused for at least five times without obvious deterioration of its catalytic activity or structural integrity.
- Zhang, Wei,Wang, Zelin,Zhao, Yufei,Miras, Haralampos N.,Song, Yu-Fei
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p. 5466 - 5474
(2019/11/13)
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- Amino- and sulfo-bifunctionalized hyper-crosslinked organic nanotube frameworks as efficient catalysts for one-pot cascade reactions
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In this paper, novel amino- and sulfo-bifunctionalized hyper-crosslinked organic nanotube frameworks (H-ONTFs) were directly prepared by templating core-shell bottlebrush copolymers via a Friedel-Crafts (F-C) alkylation reaction, in which the acidic sites were anchored into the wall of nanotubes and basic sites were introduced onto the inner layer wall of nanotubes through a rational molecular design strategy. The resulting acid-base bifunctionalized H-ONTFs showed excellent catalytic activities for one-pot deacetalization-Knoevenagel cascade reactions due to their open-ended structure, large surface area and good multi-porosity interconnectivity.
- Meng, Guojie,Gao, Shengguang,Liu, Ying,Zhang, Li,Song, Chunmei,Huang, Kun
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supporting information
p. 2269 - 2273
(2019/02/05)
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- Sulfuric acid heterogenized on magnetic Fe3O4 nanoparticles: A new and efficient magnetically reusable catalyst for condensation reactions
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Immobilized sulfuric acid on magnetic Fe3O4 nanoparticles (Fe3O4 MNPs-OSO3H) as a new solid acid nanocomposite was successfully synthesized and its catalytic activity in a series of condensation reactions was studied. High catalytic activity, simple separation from reaction mixture by an external magnet and good reusability are several eco-friendly advantages of this catalytic system. It is noteworthy that this catalytic system is applicable to a wide range of spectrum of aromatic aldehydes, and the desired products were obtained in good to excellent yields under mild conditions. The use of ecofriendly solvents makes also this synthetic protocol ideal and fascinating from the environmental point of view.
- Shiri, Lotfi,Zarei, Setare,Kazemi, Mosstafa,Sheikh, Davood
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- l-Lysine Functionalized Polyacrylonitrile Fiber: A Green and Efficient Catalyst for Knoevenagel Condensation in Water
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Abstract: The l-lysine functionalized polyacrylonitrile fiber (PANLF) was prepared by grafting the l-lysine into a commercially available polyacrylonitrile fiber and showed highly catalytic activity for Knoevenagel condensation reaction. With low temperature (45?°C) and short reaction time (1?h), the fiber catalyst was well applicable to Knoevenagel condensation of a wide range of aldehydes and the yields could reach up to 99%. Interestingly, only in water could the reaction take place smoothly (with a yield of 88%) and a polar micro-environment promoted reaction process had been proposed to explain this phenomenon. Besides, the fiber catalyst has advantages of easy preparation, high functional degree, strong mechanical strength and thermal stability, etc. And it can be reused at least 5 times without further treatment and performed well in scaled-up experiment (amplified 50 times) and flow chemistry experiment (no loss of catalytic activity after 48?h), which indicates its potential application in industry application. Graphical Abstract: [Figure not available: see fulltext.].
- Li, Pengyu,Liu, Yuanyuan,Ma, Ning,Zhang, Wenqin
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p. 813 - 823
(2018/01/27)
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- Asymmetric Reaction of p-Quinone Diimide: Organocatalyzed Michael Addition of α-Cyanoacetates
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Hitherto unknown catalytic enantioselective transformation of p-quinone diimides is achieved using chiral bifunctional organic molecules. Bifunctional thiourea compounds catalyze the Michael addition of cyanoacetates with excellent yields and enantioselec
- Reddy, Sivakumar N.,Reddy, Venkatram R.,Dinda, Shrabani,Nanubolu, Jagadeesh Babu,Chandra, Rajesh
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supporting information
p. 2572 - 2575
(2018/05/17)
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- Polyoxoniobates as a superior Lewis base efficiently catalyzed Knoevenagel condensation
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The outstanding basicity of negative charged Lindqvist type Polyoxoniobate K7HNb6O19·13H2O (Nb6) have been proved experimentally as well as by theoretical NBO calculations, the results insights high electron density on terminal and bridging oxygen atoms of niobate anion. The most negative Natural Bond Orbital charge (NBO) of oxygen in Nb6 is ?1.001, which is a much more negative value than those reported in other polyoxometalates, that corroborates its high basicity thus likely to be employed as a strong base catalyst. Experimental study suggests that Nb6 can efficiently catalyze Knoevenagel condensation of various carbonyl compounds with active methylene compounds neglecting the steric and electronic effect of aromatic aldehydes under mild conditions. Kinetic test shows that Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate exhibits second-order kinetics in the presence of Nb6 and the calculated activation energy is 43.3 kJ mol?1. Meanwhile, a proper mechanism according to the NBO study speculates that the most negative charged terminal oxygens in Nb6 would be pivotal in this transformation.
- Xu, Qiaofei,Niu, Yanjun,Wang, Guan,Li, Yingguang,Zhao, Yuan,Singh, Vikram,Niu, Jingyang,Wang, Jingping
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- Isocyanate-functionalized starch as biorenewable backbone for the preparation and application of poly(ethylene imine) grafted starch
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Reactive supports provide versatile platforms for surface decoration, affording various functional materials widely used in chemical and biological research. Considering the biodegradability, biocompatibility, and economy, starch is a suitable support med
- Fu, Lixia,Peng, Yanqing
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p. 1547 - 1554
(2017/07/18)
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- PhI(OAc)2 mediated an efficient Knoevenagel reaction and their synthetic application for coumarin derivatives
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A phenyliododiacetate (PhI(OAc)2) mediated an efficient and novel protocol for the Knoevenagel reaction has been successfully accomplished. A base free, simple and straightforward method afforded wide substrate scope and good functional group tolerance, having high yields (80–92%) under environmentally benign and mild reaction conditions.
- Khan, Danish,Mukhtar, Sayeed,Alsharif, Meshari A.,Alahmdi, Mohammed Issa,Ahmed, Naseem
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supporting information
p. 3183 - 3187
(2017/07/18)
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- One methyl group makes a major difference: Shape-selective catalysis by zeolite nanoreactors in liquid-phase condensation reactions
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The precise sizes of zeolites' micropores can induce sharp shape/size-selectivity with precision of less than 1 ? in gas-phase reactions, e.g. methanol to olefin reactions (MTO). However, it is still a major challenge and an unachieved task in liquid-phas
- Liu, Chang,Cao, Changyan,Liu, Jian,Wang, Xiaoshi,Zhu, Yanan,Song, Weiguo
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p. 17464 - 17469
(2017/09/01)
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- Reactivity of Nitroalkyl Anions Addition to Substituted Benzylidenecyanoacetates: Electrophilicity Parameters and Free Energy Relationships
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The kinetics of the reactions of benzylidenecyanoacetates 1a–d (X = H, Me, OMe, and NMe2) with nitroalkyl anions 2a–c have been studied in aqueous solution at 20°C. The second-order rate constants are used to evaluate the electrophilicity param
- Azaiez,Dhahri,Boubaker
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p. 847 - 858
(2017/10/31)
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- Highly stable naphthalene core based novel cleft-shaped strain molecule: Influence of intermolecular H-bonding architectures
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The significance of intermolecular classical and non-classical H-bonding interactions in the stabilization of a naphthalene core based conformationally rigid cleft-shaped 1,5-dioxocin (BNAP) is presented here. The importance of H-bonding interactions to a
- Panja, Sumit Kumar,Dwivedi, Nidhi,Saha, Satyen
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p. 59574 - 59581
(2016/07/06)
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- Fe3O4@UiO-66-NH2 core–shell nanohybrid as stable heterogeneous catalyst for Knoevenagel condensation
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Magnetic separation is an attractive alternative to filtration or centrifugation for separating solid catalysts from a liquid phase. Here, core-shell Fe3O4@UiO-66-NH2nanohybrids with well-defined structures were constructe
- Zhang, Yanmei,Dai, Tianlin,Zhang, Fan,Zhang, Jing,Chu, Gang,Quan, Chunshan
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p. 2106 - 2113
(2017/01/16)
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- Amine-functionalized ionic liquid-based mesoporous organosilica as a highly efficient nanocatalyst for the Knoevenagel condensation
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A novel amine-functionalized ionic liquid-based periodic mesoporous organosilica (PMO-IL-NH2) was prepared and characterized and its catalytic performance was investigated in the Knoevenagel reaction. PMO-IL-NH2 was prepared by simul
- Elhamifar, Dawood,Kazempoor, Somayeh,Karimi, Babak
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p. 4318 - 4326
(2016/07/06)
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- Synthesis and characterization of ionic liquid based bifunctional periodic mesoporous organosilica supported potassium carbonate as very efficient nanocatalyst for the Knoevenagel condensation
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A novel ionic liquid based bifunctional periodic mesoporous organosilica supported potassium carbonate (BPMO-IL-KCO3) is prepared, characterized and its catalytic efficiency is studied in the Knoevenagel reaction. The BPMO-IL-KCO3 wa
- Elhamifar, Dawood,Kazempoor, Somayeh
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- Dicalcium phosphate dehydrate DCPD as a highly efficient and reusable catalyst for Knoevenagel condensation
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We have described the catalytic activities of dicalcium phosphate dihydrate (DCPD) in the condensation reaction of various substituted benzaldehydes with active methylene compound malononitrile. The influences of reaction conditions on the corresponding c
- Benzekri, Zakaria,El Mejdoubi, Khalid,Boukhris, Said,Sallek, Brahim,Lakhrissi, Brahim,Souizi, Abdelaziz
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supporting information
p. 442 - 451
(2016/04/05)
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- Potassium fluoride/K10-montmorillonite nanostructure as a green and reusable catalyst under mild reaction conditions for the knovenagel condensation
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Potassium fluoride (KF)/montmorillonite (K10-MMT) nanostructure acts as an active heterogeneous base catalyst for Knovenagel condensation. Here we have described the catalytic activities of KF/K10 nanostructure in the condensation reaction of various subs
- Ghanei, Mercedeh,Khalilzadeh, Mohammad A.,Hashemi, Mohammad M.
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p. 665 - 669
(2016/05/09)
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- Polyoxometalate-Intercalated Layered Double Hydroxides as Efficient and Recyclable Bifunctional Catalysts for Cascade Reactions
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The polyoxometalate (POM) intercalated layered double hydroxides (LDHs) have been widely used as heterogeneous catalysts. However, the application of POM-LDHs as bifunctional catalysts for cascade reaction has seldom been studied compared to the noble-metal-based catalysts. Herein, a series of POM-LDHs catalysts of Tris-LDH-X4(PW9)2 (X=Mn, Fe, Co, Ni, Cu, and Zn; Tris=Tris(hydroxymethtyl)aminomethane) have been prepared. The efficacy of Tris-LDH-Zn4(PW9)2 as efficient bifunctional catalyst has been demonstrated for cascade reactions involving oxidation of benzyl alcohol to benzaldehyde followed by Knoevenagel condensation with ethyl cyanoacetate to produce benzylidene ethyl cyanoacetate. The combination of POM's redox/acidic sites and LDHs's basic sites led to a composite catalyst with excellent activity (99 %) and selectivity (≥99 %) under mild and soluble-base-free conditions. This work offers a new design strategy for the fabrication of efficient bifunctional catalysts for the promotion of one-pot cascade reactions.
- Liu, Kai,Xu, Yanqi,Yao, Zhixiao,Miras, Haralampos N.,Song, Yu-Fei
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p. 929 - 937
(2016/03/15)
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- Efficient preparation of Zr(IV)-salen grafted mesoporous MCM-41 catalyst for chemoselective oxidation of sulfides to sulfoxides and Knoevenagel condensation reactions
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Zr(IV)-salen-MCM-41 was prepared by reaction of NH2-MCM-41 with salicylaldehyde to afford Schiff base ligands. Thereafter, ZrOCl2·8H2O was reacted with the Schiff base ligands for complex formation. The structural properti
- Hajjami, Maryam,Ghorbani, Farshid,Rahimipanah, Sedighe,Roshani, Safoora
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p. 1852 - 1860
(2015/11/17)
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- First report of the application of simple molecular complexes as organo-catalysts for Knoevenagel condensation
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A series of molecular complexes have been designed, synthesized and used as organo-catalysts for the first time for very efficient Knoevenagel condensation. Molecular complexes are thermally stable, easily recyclable, and have a low cost of preparation. T
- Panja, Sumit Kumar,Dwivedi, Nidhi,Saha, Satyen
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p. 65526 - 65531
(2015/08/18)
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- Facile One-Pot Synthesis of Amine-Functionalized Mesoporous Silica Nanospheres for Water-Medium Knoevenagel Reaction Under Microwave Irradiation
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Amine-functionalized mesoporous silica nanospheres (~80 nm) (NH2-MSNS) were prepared by a co-condensation method using tetraethyl orthosilicate and aminopropyltrimethoxysilane. The catalytic activities of the NH2-MSNS catalysts were
- Zhu, Fengxia,Sun, Xiaojun,Lou, Fengwen,An, Litao,Zhao, Pusu
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p. 1072 - 1079
(2015/02/05)
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- Efficient tandem synthesis of a variety of pyran-annulated heterocycles, 3,4-disubstituted isoxazol-5(4H)-ones, and α,β-unsaturated nitriles catalyzed by potassium hydrogen phthalate in water
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A variety of 4H-chromenes, benzochromenes, 4,5-dihydropyrano[3,2-c]chromenes, 4H-pyran-3-carboxylates, and 3,4-disubstituted isoxazol-5(4H)-ones have been synthesized in high yields by using potassium hydrogen phthalate (KHP) as an inexpensive, commercially available catalyst. It was found that the three-component tandem reaction enabled synthesis of pyran-annulated heterocycles in water at 50 °C. 3,4-Disubstituted isoxazol-5(4H)-ones were synthesized by use of 10 mol% KHP in water at room temperature. Also, treatment of methylene-containing compounds (malononitrile or ethyl cyanoacetate) with aromatic aldehydes in the presence of 5 mol% KHP resulted in α,β-unsaturated nitriles. The procedure is an easily performed, straightforward method for synthesis of a variety of pyran-annulated compounds, isoxazol-5(4H)-one-containing heterocycles, and Knoevenagel adducts. The reaction is safe, uses mild conditions, and is environmentally benign. Other notable advantages are reuse of the catalyst, no use of hazardous organic solvents, and ease of work-up.
- Kiyani, Hamzeh,Ghorbani, Fatemeh
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p. 7847 - 7882
(2015/02/19)
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- Stereoselective synthesis of vic-halohydrins and an unusual Knoevenagel product from an organocatalyzed aldol reaction: A non-enamine mode
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Stereoselective synthesis by an aldol reaction between chloroacetone and aldehyde was studied using a synthesized chiral organocatalyst and triethylamine. The reaction gave α-chloro-β-hydroxy ketones in excellent yield with high anti selectivity and enantioselectivity. The chiral organocatalyst was also used in the Knoevenagel reaction, which gave α-cyano-β-hydroxy ketones at a low temperature and the usual Knoevenagel product at a high temperature. Both products were obtained in good to moderate yield with good anti selectivity in the case of α-cyano-β-hydroxy ketone derivatives.
- Thorat,Goswami,Sondankar,Bhusare
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p. 1093 - 1100
(2015/07/01)
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- Discovery, stereospecific characterization and peripheral modification of 1-(pyrrolidin-1-ylmethyl)-2-[(6-chloro-3-oxo-indan)-formyl]-1,2,3,4-tetrahydroisoquinolines as novel selective κ opioid receptor agonists
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A novel series of 1-(pyrrolidin-1-ylmethyl)-2-[(3-oxo-indan)-formyl]-1,2,3,4-tetrahydroisoquinoline derivatives maj-3a-maj-3u were synthesized and evaluated in vitro for their binding affinity at κ-opioid receptors. Maj-3c displayed the highest affinity for κ-opioid receptors (Ki = 0.033 nM) among all the compounds evaluated. Furthermore, all four stereoisomers of compound 3c were prepared, and (1S,18S)-3c was identified as the most potent (Ki = 0.0059 nM) κ-opioid receptor agonist among the four stereoisomers. Maj-3c produced significant antinociception (ED50 = 0.000406 mg kg-1) compared to U-50,488H and original BRL 52580 in the acetic acid writhing assay, but its strong sedative effect (ED50 = 0.000568 mg kg-1) observed in the mouse rotation test reduced its druggability. To minimize the central nervous system side effects, a series of hydroxyl-containing analogs of maj-3c were synthesized, and maj-11a was found to be a potent κ-opioid receptor agonist (Ki = 35.13 nM). More importantly, the dose for the sedative effect (ED50 = 9.29 mg kg-1) of maj-11a was significantly higher than its analgesic dose (ED50 = 0.392 mg kg-1), which made it a promising peripheral analgesic candidate compound with weak sedative side effects.
- Gan, Zong-Jie,Wang, Yu-Hua,Xu, Yun-Gen,Guo, Ting,Wang, Jun,Song, Qiao,Xu, Xue-Jun,Hu, Shi-Yuan,Wang, Yu-Jun,Wang, De-Chuan,Sun, De-Zhu,Zhang, Di,Xi, Tao,Li, Hao-Dong,Zhang, Hai-Bo,Hang, Tai-Jun,Lu, Hong-Guo,Liu, Jing-Gen
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p. 5656 - 5673
(2015/05/27)
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- Direct Three-Component Synthesis of α-Cyano Acrylates Involving Cascade Knoevenagel Reaction and Esterification
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A direct three-component approach has been developed for the synthesis of α-cyano acrylates starting from aldehydes, alcohols and α-cyano acetamide by employing cyanuric chloride as an organocatalyst. A class of structurally diverse α-cyano acrylates have been provided with good to excellent yields via the cascade transformation of Knoevenagel condensation and amide esterification.
- Jing, Yanfeng,Meng, Jiaojiao,Liu, Yunyun,Wan, Jie-Ping
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p. 1194 - 1198
(2015/11/02)
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- Alum-Cs2CO3 as a new recyclable solid base catalyst for the efficient syntheses of arylidenemalononitriles, esters and arylcinnamic acids in water
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The condensation between aromatic aldehydes and malononitrile, ethylcyanoacetate and malonic acid for the syntheses of arylidenemalononitriles, arylidenemalonic acid esters and aryl cinnamic acids in water using alum-Cs2CO3 as a solid support catalyst has been described. Alum-Cs2CO3 was found to be a highly active, stable and recyclable catalyst under reaction conditions.
- Taduri, Ashok Kumar,Devi, B. Rama
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p. 1938 - 1942
(2014/06/09)
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- Synthesis, characterization and heterogeneous catalytic activity of diamine-modified silica-coated magnetite-polyoxometalate nanoparticles as a novel magnetically-recoverable nanocatalyst
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Magnetite-polyoxometalate hybrid nanomaterials, Fe3O 4@SiO2@NH-NH2-PW, was prepared by grafting of H3PW12O40 on the diamine-functionalized Fe 3O4 magnetite
- Shahbazi, Fomeida,Amani, Kamal
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- Novel and versatile solid superbases derived from magnesium-zirconium composite oxide and their catalytic applications
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Versatile solid superbases were derived from magnesium-zirconium composite oxide and KOH through thermal treatment in a N2 flow. The magnesium-zirconium composite oxide was prepared by a modified co-precipitation technique with reflux-digestion in basic solution and then mixed with KOH through grinding. The as-prepared solid superbases were characterized by low-temperature N2 physisorption, powder X-ray diffraction, and Fourier transformation infrared spectrophotometry. The superbasic sites were characterized by the use of Hammett indicators and CO2 temperature-programmed desorption methods. We found that there are ample superbasic sites (0.590 mmol g-1) on the surface with strength in the 26.5 ≤ H- 33.0 range. The as-prepared solid superbase catalyst was found to show excellent catalytic activity towards Knoevenagel condensation, Michael addition and transesterification reactions. The findings open up a new route for the synthesis of new functional superbases using composite oxides prepared by reflux-digestion in basic solution as supports.
- Zhao, Jin,Xie, Jun,Au, Chak-Tong,Yin, Shuang-Feng
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p. 6159 - 6164
(2014/01/23)
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- Synthesis and antibacterial activity of ethyl 2-amino-6-methyl-5-oxo-4- aryl-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carboxylate
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The three-component reaction of 4-hydroxy-1-methyl-2(1H)-quinolinone, aromatic aldehydes and ethyl cyanoacetate was carried out in the presence of a catalytic amount of 4-dimethyl aminopyridine (DMAP) in aqueous ethanol. The reactions result in the format
- Asghari, Sakineh,Ramezani, Samaneh,Mohseni, Mojtaba
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p. 431 - 434
(2014/03/21)
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- One pot, three-component synthesis of novel 3,4-dihydrophthalazin-2(1H)-yl- 4-phenyl-4H-pyrans
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Green and efficient one pot, three-component synthesis of novel 2-amino-6-(1,4-dioxo-3,4-dihydrophthalazin)-2(1H)-yl-4-phenyl-4H-pyran-3, 5-dicarbonitriles 6 has been developed by condensing 3-(1,4-dioxo-3,4- dihydrophthalazin-(1H)-yl)-3-oxopropanenitrile 3, benzaldehydes 4 and active methylene compounds 5 using l-proline as catalyst in EtOH at RT.
- Kumar, P. Praveen,Reddy, Y. Dathu,Reddy, Ch. Venkata Ramana,Devi, B. Rama,Dubey
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p. 2177 - 2182
(2014/04/17)
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- Synthesis of novel nithiazine analogues containing the 1,4-dihydropyridine structure, and their bioactivity as insecticides
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A series of novel nithiazine analogues bearing the 1,4-dihydropyridine structure have been designed and synthesized by reaction of nithiazine, malononitrile or ethyl cyanoacetate, and benzaldehyde. The synthesized compounds were identified by 1
- Tian, Zhongzhen,Cui, Shuxia,Xu, Zhiping
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p. 1053 - 1059
(2014/05/06)
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- The discovery of potent, orally bioavailable pyrimidine-5-carbonitrile-6- alkyl CXCR2 receptor antagonists
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A hit-to-lead optimisation programme was carried out on the Novartis archive screening hit, pyrimidine 2-((2,6-dichlorobenzyl)thio)-5-isocyano-6- phenylpyrimidin-4-ol 4, resulting in the discovery of CXCR2 receptor antagonist 2-((2,3-difluorobenzyl)thio)-
- Porter, David W.,Bradley, Michelle,Brown, Zarin,Charlton, Steven J.,Cox, Brian,Hunt, Peter,Janus, Diana,Lewis, Sarah,Oakley, Paul,O'Connor, Des,Reilly, John,Smith, Nichola,Press, Neil J.
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p. 3285 - 3290
(2014/07/22)
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- Kinetic insights of DNA/RNA segment salts catalyzed knoevenagel condensation reaction
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In this work, we demonstrated that (i) salts of RNA/DNA segments were capable of catalyzing Knoevenagel condensation at physiological pH 7.0 with efficiency comparable to one of the best enzymes, porcine pancreatic lipase (PPL); and (ii) a broad scope of
- Li, Weina,Fedosov, Sergey N.,Tan, Tianwei,Xu, Xuebing,Guo, Zheng
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p. 3294 - 3300
(2014/12/11)
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