- 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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- Bismuth (III) Triflate: A Mild, Efficient Promoter for the Synthesis of Trisubstituted Alkenes through Knoevenagel Condensation
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In this work, smooth efficient and eco-friendly two component coupling method is reported for the synthesis of Knoevenagel Condensation product in presence of Bi(OTf)3 catalyst under solvent free condition. Catalyst has participated in condensation between substituted aldehydes (aromatic and hetero-aromatic) and active methylene compounds (ethyl cyanoacetate, malononitrile and cyanoacetamide) effectively to generate an excellent yield of the product. Bi(OTf)3 catalyst is stable, inexpensive and easily available was used for four times in this reaction without loss of catalytic activity. [Formula Presented]
- Datta, Arup
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p. 843 - 849
(2020/11/25)
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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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- 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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- 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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- New magnetic nanocatalyst containing a bis-dicationic ionic liquid framework for Knoevenagel condensation reaction
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Bis[(3-aminopropyl)triethoxysilane]dichloride immobilized on magnetic nano-γ-Fe2O3@SiO2 has been prepared. After characterization, the reagent was used for efficient promotion of the Knoevenagel reaction, achieving high re
- Karimi-Chayjani, Reyhaneh,Daneshvar, Nader,Shirini, Farhad,Tajik, Hassan
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p. 2471 - 2488
(2019/02/24)
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- Polymer immobilized [Mg@PS-anthra] complex: An efficient recyclable heterogeneous catalyst for the incorporation of carbon dioxide into oxiranes at atmospheric pressure and Knoevenagel condensation reaction under solvent free condition
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Chemical fixation of CO2 into the organic molecules is very challenging from the perspective of greenhouse gas consumption and manufacturing of chemicals with C1 backbone. The process was developed with the synthesis of an efficient polystyrene
- Mondal, Ranjan Kumar,Riyajuddin, Sk,Ghosh, Aniruddha,Ghosh, Swarbhanu,Ghosh, Kaushik,Islam, Sk.Manirul
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p. 322 - 332
(2018/12/11)
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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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- Synthesis and characterization of sulfamic acid supported on Fe3O4 nanoparticles: A green, versatile and magnetically separable acidic catalyst for oxidation reactions and Knoevenagel condensation
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Sulfamic acid immobilized on diethylenetriamine functionalized Fe3O4 nanoparticles (SA-DETA-Fe3O4) was successfully prepared and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), thermo gravimetric analysis (TGA), X-Ray diffraction (XRD) and scanning electron microscopy (SEM). The sulfamic acid was found as a magnetically separable and highly active catalyst for the oxidative coupling thiols, oxidation of sulfides. Furthermore, the SA-DETA-Fe3O4 showed the high catalytic activity in Knoevenagel condensation of aromatic aldehydes with active methylene compounds (malononitrile and ethyl cynoacetate). The nanosolid catalyst could be easily recovered by a simple magnetic separation and reused for many cycles without deterioration in catalytic activity.
- Shiri, Lotfi,Narimani, Hojatollah,Kazemi, Mosstafa
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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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- 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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- Magnetic Fe3O4 nanoparticles supported amine: a new, sustainable and environmentally benign catalyst for condensation reactions
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Abstract: Diethylenetriamine immobilized on magnetic Fe3O4 nanoparticles (DETA-Fe3O4) was successfully prepared as a new and well dispersed magnetically separable amine catalyst. The structure of the resulting catalyst was well characterized by a series of analysis techniques such as FT-IR, SEM, EDX, VSM, TGA and XRD. The catalytic activity of DETA-Fe3O4 was evaluated with Knoevenagel condensation of active methylene compounds with aromatic aldehydes. Interestingly, the cyclocondensation of anthranilamide and aldehydes were effectively catalyzed by DETA-Fe3O4 in water, and the desired products (2,3-dihydroquinazoline-4(1H)-ones) were afforded in admirable yields. Catalysis research under aqueous medium (water) also makes this synthetic protocol ideal and fascinating from the environmental point of view. The amine catalyst can be magnetically recovered after the reaction and can be reused many times without appreciable decrease in activity.
- Shiri, Lotfi,Kazemi, Mosstafa
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p. 4813 - 4832
(2017/07/22)
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- Synthesis and characterization of bromine source supported on magnetic Fe3O4 nanoparticles: A new, versatile and efficient magnetically separable catalyst for organic synthesis
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Tribenzylammonium tribromide supported onto magnetic nanoparticles (Br3-TBA-Fe3O4) as a bromine source was successfully synthesized and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and vibrating sample magnetometry. The synthesized catalyst is shown to be a versatile and highly efficient heterogeneous catalyst for the Knoevenagel condensation and synthesis of 2,3-dihydroquinazolin-4(1H)-one and polyhydroquinoline derivatives. To the best of the authors' knowledge, this is the first report of the use of a bromine source immobilized on Fe3O4 nanoparticles as a magnetically separable catalyst for these reactions. The nanosolid catalyst can be magnetically recovered and reused readily several times without significant loss in catalytic efficiency.
- Shiri, Lotfi,Ghorbani-Choghamarani, Arash,Kazemi, Mosstafa
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- Adenine-Based Coordination Polymers: Synthesis, Structure, and Properties
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A solvothermal reaction of metal nitrate (M = Zn, Cd), cyclohexanedicarboxylic acid, and adenine resulted in the isolation of three new coordination polymers, [Zn4(1,4-CHDA)2.5(ad)3·2H2O] 7H2O 2DMA (C
- Sushrutha,Hota, Raghunandan,Natarajan, Srinivasan
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supporting information
p. 2962 - 2974
(2016/07/14)
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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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- 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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- 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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- Amines functionalized C60 as solid base catalysts for Knoevenagel condensation with high activity and stability
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Four kinds of amines functionalized C60 were prepared through an amination reaction of C60 with organic amines. Their surface structures and basic properties were studied by Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD) with CO2 as the probe molecule. When used as solid base catalysts, N-aminoethylpiperazine functionalized C60 (C60-AEP) showed the best catalytic activity in the Knoevenagel condensation reaction due to the highest basic strength. In addition, the C60-AEP catalyst also showed impressive catalytic stability. All these features endowed C60-AEP with characteristics of both homogeneous and heterogeneous catalysts. More interestingly, chiral l-lysine functionalized C60 (C60-L-L) can be used for asymmetric intermolecular aldol reactions.
- Sun, Yongbin,Cao, Changyan,Huang, Peipei,Yang, Shuliang,Song, Weiguo
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p. 86082 - 86087
(2015/11/03)
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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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- A mechanochemical approach for the construction of carbon-carbon double bonds: Efficient syntheses of aryl/heteroaryl/aliphatic acrylates and nitriles
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An efficient method for the construction of carbon-carbon double bond has been developed from aromatic aldehydes and compounds with active methylene moieties in the presence of catalytic amount of solid sodium ethoxide via mechanochemical approach. This c
- Jayalakshmi, Lakshmi Narayanan,Karuppasamy, Ayyanar,Stalindurai, Kesavan,Sivaramakarthikeyan, Ramar,Devadoss, Vellasamy,Ramalingan, Chennan
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p. 1322 - 1330
(2017/12/02)
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- DENGUE AND WEST NILE VIRUS PROTEASE INHIBITORS
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Compounds and methods of treating or preventing a Flavivirus infection in a subject are provided. The methods comprise administering to the subject a therapeutically effective amount of a compound as described herein. The methods are useful in treating and/or preventing Flavivirus infections such as, for example, West Nile Virus, Dengue Virus, and Japanese Encephalitis Virus. Methods of inhibiting a Flavivirus protease in a cell are also provided.
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Page/Page column 32
(2014/10/18)
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- Applications of caged-designed proton sponges in base-catalyzed transformations Dedicated to Professor Milan Kratochvíl for his 90th birthday anniversary.
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Superbasic properties of caged proton sponges (PSs) - substituted diazatetracyclo[4.4.0.13,10.15,8]dodecanes (DTDs) - were utilized in Knoevenagel and Claisen-Schmidt condensations, the Pudovik reaction, and Michael addition. This investigation covers the influence of the solvent, reaction temperature, catalyst loadings as well as the electronic properties of substituents upon the reaction. Moreover, we provided an activity comparison between our new base and a well-known and commercially available proton sponge (DMAN). The basicity (in MeCN) of our chosen DTD (pKBH+=21.7±0.1) exceeded the prototypal PS - 1,8-bis(dimethylamino)naphthalene (DMAN, pKBH+=18.6), by three orders of magnitude. We proved that DTDs are reasonably active species in monitored reactions, which is a consequence of a hydrogen bridge angle (~130°) between the two nitrogen atoms and the captured proton. We present here syntheses of aminoindolizine, substituted 4H-chromene, and flavanones, and the unexpected formation of a bis-addition product formed after Michael addition, all under mild conditions.
- Galeta, Juraj,Potá?ek, Milan
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- One-pot synthesis of potassium-loaded MgAl oxide as solid superbase catalyst for Knoevenagel condensation
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We report a new strategy for one-pot synthesis of potassium-loaded MgAl oxides using KOH to adjust the pH value of the reaction system. The as-prepared solid superbases were studied by N2 physisorption method, energy-dispersive X-ray spectrosco
- Zhao, Jin,Xie, Jun,Au, Chak-Tong,Yin, Shuang-Feng
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- Novel magnetic nanoparticles Fe3O4-immobilized domino Knoevenagel condensation, Michael addition, and cyclization catalyst
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The synthesis, characterization and applications of guanidine supported on magnetic nanoparticles Fe3O4 (MNPs-Guanidine) as a novel magnetically separable base nanocatalyst are described. We have studied the application of this new c
- Rostami, Amin,Atashkar, Bahareh,Gholami, Hoshyar
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- Mesoporous Borated Zirconia: A Solid Acid-Base Bifunctional Catalyst
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The development and use of reusable solid catalysts for the selective organic transformation in solvent-free or environmentally benign solvent media is the key interest of modern frontier science. Herein a facile low temperature aqueous solution based chemical route for the synthesis of mesoporous borated zirconia, an acid-base bifunctional solid catalyst, using aqueous zirconium ammonium carbonate complex and borax in presence of cetyltrimethylammonium bromide is presented. The material has a very high surface area and acidity with weak basicity. The catalytic activity of the material was investigated for the solvent-free Knoevenagel condensation reaction of benzaldehyde/substituted benzaldehyde and malononitrile/cyano ethylacetate to confirm the acid-base bifunctionality. High yield (>90%) of the corresponding benzylidene was obtained within 15-30min at room temperature. The evidence that the high catalytic activity is a result of acid-base bifunctionality of the synthesized borated zirconia material was further supported by performing Claisen-Schmidt condensation of benzaldehyde and acetophenone. The methodology was also extended for targeted synthesis of cinnamyl ethyl ester and coumarin or coumarin ester; and resulted in a good yield.
- Sinhamahapatra, Apurba,Pal, Provas,Tarafdar, Abhijit,Bajaj, Hari C.,Panda, Asit Baran
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p. 331 - 338
(2013/03/14)
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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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experimental part
p. 1067 - 1070
(2012/10/18)
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- Polystyrene-supported pyridinium 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 pyridine followed by reaction with aluminium chloride. This Lewis acidic ionic liquid is an environmentally friendly heterogeneous c
- Boroujeni, Kaveh Parvanak,Jafarinasab, Mina
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experimental part
p. 429 - 431
(2012/09/22)
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- A systematic study on Knoevenagel reaction and Nazarov cyclization of less reactive carbonyl compounds using rare earth triflates and its applications
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A systematic study of Knoevenagel reaction and Nazarov cyclization was made on variety of less reactive carbonyl compounds such as β-ketoesters, 1,3-diketones and cyclic active methylene compounds using Yb(OTf)3 as the catalyst. Recycling study confirms reusability of the catalyst without much loss of activity.
- Ilangovan,Muralidharan,Maruthamuthu
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experimental part
p. 1000 - 1006
(2012/02/05)
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- Synthesis and biological activity of 2-amino-4H-pyrimido[2,1-b][1,3] benzothiazole-3-carboxylates
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3-Chloro-4-fluoro aniline (1) on reaction with potassium thiocyanate (2) followed by the addition of bromine in acetic acid medium yielded 2-amino 5-chloro-6-fluro[2,1-b][1,3]benzothiazole (3). Compound 3 when treated with β-cyanoester undergoes cycloaddi
- Chaithanya,Vaidya,Nagendrappa
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experimental part
p. 1618 - 1620
(2012/01/05)
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- Lipase-catalysed tandem Knoevenagel condensation and esterification with alcohol cosolvents
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Six lipases were screened for their ability to catalyse the Knoevenagel condensation between benzaldehyde and methyl cyanoacetate. Lipase from porcine pancreas tolerated a variety of functional groups on the aromatic ring, produced the highest yields, and
- Lai, Yi-Feng,Zheng, Hui,Chai, She-Jie,Zhang, Peng-Fei,Chen, Xin-Zhi
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supporting information; experimental part
p. 1917 - 1918
(2010/12/24)
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- Knoevenagel condensation catalyzed by chemo-selective Ni-nanoparticles in neutral medium
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Recyclable Ni-nanoparticles provides an efficient, economic and rapid method for catalyzing Knoevenagel condensation of aldehydes with an active methylene compound at room temperature. The method offers high yield preferably in case of aromatic aldehydes and proceed well in neutral medium. This method provides a wide range of substrate applicability and simple workup procedure. The products need no further purification and the process is environmentally benign.
- Kumar, Ajeet,Dewan, Manika,Saxena, Amit,De, Arnab,Mozumdar, Subho
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experimental part
p. 679 - 683
(2010/07/06)
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- A novel and green method for the synthesis of highly substituted isoquinoline derivatives in ionic liquid
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(Chemical Equation Presented) A series of new highly substituted isoquinoline derivatives was obtained from the reaction of 2-(1-substituted piperidin-4-ylidene)malononitrile, benzaldehyde and malononitrile or cyanoacetate in ionic liquid at 50°C. This no
- Wang, Xiang-Shan,Wu, Jian-Rong,Li, Qing,Zhang, Mei-Mei
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body text
p. 1355 - 1363
(2010/03/26)
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- Facile regioselective green synthesis of triazolo [4,3-a] pyrimidines in aqueous medium
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Regioselectivity is investigated in multi-component reaction of amino triazole, carbonyl compounds and α-cyano esters derivative and exclusive synthesis of triazolopyrimidines is developed in aqueous medium in excellent yields in shorter period using microwaves or ultrasonic waves. Path and mechanism of the reaction has also been discussed. The operational simplicity, environmental friendly conditions, regioselective formation of target product, high yield in significantly very short reaction time, are major benefits.
- Dandia, Anshu,Singh, Ruby,Singh, Dharmendra,Arya, Kapil
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scheme or table
p. 100 - 105
(2010/04/23)
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- Reaction of ethyl cyanoacetate with benzal-4-acetylanilines: An unexpected result
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Reaction of ethyl cyanoacetate with benzal-4-acetylanilines 1a-10a, the compounds containing both azomethine and ketone linkages, in equimolar ratio, in the presence of pyridine yields solid products, which have been characterized as ethyl benzal-cyanoacetate and its derivatives 1b-10b on the basis of elemental analysis and spectral studies. The reaction of 1a-10a with two moles of ethyl cyanoacetate also results in the formation of the same products 1b-10b, by an unexpected attack of ethyl cyanoacetate on azomethine linkage only rather than on both the reactive centres i.e. carbon-nitrogen double bond and carbon-oxygen double bond.
- Sidhu, Anjali,Rai, Mangat
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p. 778 - 780
(2008/12/20)
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- On water: An efficient Knoevenagel condensation using 12-tungstophosphoric acid as a reusable green catalyst
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12-Tungstphosphoric acid is found to be an efficient, environmentally attractive, and reusable catalyst for Knoevenagel condensation of malononitrile and ethylcyanoacetate with various aldehydes. Copyright Taylor & Francis Group, LLC.
- Oskooie, Hossien A.,Heravi, Majid M.,Derikvand, Fatemeh,Khorasani, Marzieh,Bamoharram, Fatemeh F.
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p. 2819 - 2823
(2007/10/03)
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- The Knoevenagel condensation of aromatic aldehydes with malononitrile or ethyl cyanoacetate in the presence of CTMAB in water
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A new route of Knoevenagel condensation of aldehydes with malononitrile or ethyl cyanoacetate in the presence of CTMAB in water is described. CTMAB is the most effective catalyst to increase yield among CTMAB, BTEAC and TBAI.
- Wang,Ren,Cao,Tong
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p. 673 - 677
(2007/10/03)
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- Facile and Efficient Synthesis of 2-Aminoquinoline-3-carboxylic Acid Derivatives via Reductive Cyclization of Nitro and Cyano Groups Induced by Low-valent Titanium
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A short and facile synthesis of a series of 2-aminoquinoline-3-carboxylic acid derivatives was accomplished in good yields via the intramolecular reductive cyclization of nitrocyano olefins promoted by TiCl4/Zn.
- Zhou, Longhu,Tu, Sujiang,Shi, Daqin,Dai, Guiyuan
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p. 398 - 399
(2007/10/03)
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