- A new copper-based metal-organic framework as a promising heterogeneous catalyst for chemo- and regio-selective enamination of β-ketoesters
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Assembly of 5-nitro-1,2,3-benzenetricarboxylic acid (H3nbta) with CuII in the presence of 1,3-bis(1,2,4-triazol-1-yl)propane (1,3-btp) leads to a new metal-organic framework, [Cu(Hnbta)(1,3-btp)] ·2H2O (A1), which is shown to be an efficient and recyclable heterogeneous catalyst for enamination of β-ketoesters with excellent product yields and selectivity.
- Zhao, Ying,Deng, Dong-Sheng,Ma, Lu-Fang,Ji, Bao-Ming,Wang, Li-Ya
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Read Online
- K-10 clay as a reusable catalyst for the solvent-free, MW-induced synthesis of enaminones
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A series of β-amino-a,β-unsaturated ketones and esters were synthesized in good to excellent yields from the reaction of different amines with 1,3-dicarbonyl compounds in solvent-free media using montmorillonite K-10 clay as.
- Marvi, Omid,Giahi, Masoud,Ayub, Pouran Pur,Nikpasand, Mohammad
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- Cerium(III) chloride heptahydrate (CeCl3·7H2O) as an efficient enamination catalyst in aqueous media
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Cerium(III) chloride heptahydrate CeCl3·H2O catalyzes enamination of β-dicarbonyl compounds with primary amines in aqueous medium at room temperature to afford the corresponding β-enamino ketones with high chemoselectivity.
- Khodaei,Khosropour,Kookhazadeh
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- Fabrication of Ag/γ-Fe2O3@TiO2 hollow magnetic core-shell nanospheres as highly efficient catalysts for the synthesis of β-enaminones
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Herein, we describe a method to prepare hollow magnetic mesoporous sphere catalysts (Ag/γ-Fe2O3@meso-TiO2). The core-shell strategy efficiently prevents the aggregation of Ag NPs in the high temperature calcination process and the leaching of Ag NPs for the catalytic reaction in the liquid phase. The catalyst is characterized by TEM, XRD and ICP-AES. Moreover, the catalyst exhibited improved activity for the synthesis of β-enaminones, and it could be easily recovered by an external magnet from the reaction mixture and recycled five times without any significant loss in activity.
- Huo, Hongfei,Li, Xinzhe,Zhou, Xingchun,Jiao, Lixin,Zhao, Shiling,Zhang, Le,Li, Wenzhu,Li, Shuwen,Li, Rong
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- Iodine-Promoted Construction of Polysubstituted 2,3-Dihydropyrroles from Chalcones and β-Enamine Ketones (Esters)
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A novel approach for the synthesis of a variety of polysubstituted trans-2,3-dihydropyrroles from a wide range of chalcones and β-enamine ketones (esters) via iodine-promoted tandem Michael/cyclization sequence has been developed, affording the desired products in moderate to excellent yields. This methodology is a highly efficient, convenient way to access functionalized 2,3-dihydropyrroles from readily accessible substrates under mild reaction conditions.
- Li, Yujin,Xu, Hui,Xing, Mengming,Huang, Fang,Jia, Jianhong,Gao, Jianrong
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- Zeolite (ZSM-5) as a highly efficient and heterogeneous catalyst for the synthesis of β-Enaminones and β-Enamino esters
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Several β-enaminones and β-enaminoesters have been synthesized in high yields from amine and β-diketone in the presence of Zeolite (ZSM-5) as a catalyst. This method is applicable to both cyclic and acyclic ketones with aromatic and aliphatic amines. Copyright E-Journal of Chemistry 2004-2011.
- Shekhar, Amiya,Pathak, Devendra Deo
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- Synthesis, spectral and structural characterization of cobalt(III) dithiocarbamato complexes: Catalytic application for the solvent free enamination reaction
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The syntheses, spectral, structural and catalytic properties of some new cobalt(III) complexes, [Co(mpcdt)3] (1), [Co(ppcdt)3] (2) and [Co(mppcdt)3]·0.25CHCl3 (3), derived from 4-methyl piperazine-1-carbodithioate (mpcdt), 4-phenyl piperazine-1-carbodithioate (ppcdt) and 4-(2-methoxyphenyl) piperazine-1-carbodithioate (mppcdt) have been described. A series of β-enaminoesters and β-enaminones were obtained in about 90% yield by the reactions of β-ketoesters and 1,3-diketones with aliphatic and aromatic amines using 1-2 mol% of the above cobalt(III) complexes as catalysts and these have been characterized by NMR, GC-MS and X-ray crystallography. Complexes 1, 2 and 3 are stabilized by intermolecular C-H?S interactions, leading to the formation of supramolecular architectures. Thermogravimetric analysis of complexes 1 and 2 have been investigated by TG-DTA, which indicate that cobalt sulfide is formed as the final product.
- Bharati, Pooja,Bharti,Nath,Bharty,Butcher,Singh
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- Enamination of β-dicarbonyl compounds catalyzed by CeCl 3·7H2O at ambient conditions: Ionic liquid and solvent-free media
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Enamination of a wide various primary amines was successfully carried out in the presence of catalytic amounts of cerium chloride heptahydrate in ionic liquid and solvent-free conditions as 'green' media under mild reaction conditions.
- Khodaei, Mohammad Mehdi,Khosropour, Ahmad Reza,Kookhazadeh, Mehdi
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- Solvent-free and efficient synthesis of highly functionalized cyclohexa-1,3-diene derivatives via a novel one-pot three-component reaction
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A catalyst-free and convenient approach for the preparation of cyclohexa-1,3-dienecarboxylate derivatives is described. This three-component reaction between primary amines, alkyl acetoacetate, and dibenzylideneacetone proceeds under solvent-free condition in good to excellent yields. Georg Thieme Verlag Stuttgart.
- Alizadeh, Abdolali,Rezvanian, Atieh,Mokhtari, Javad
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- Lead derivatization of ethyl 6-bromo-2-((dimethylamino)methyl)-5-hydroxy-1-phenyl-1H-indole-3-carboxylate and 5-bromo-2-(thiophene-2-carboxamido) benzoic acid as FabG inhibitors targeting ESKAPE pathogens
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Our previous studies on FabG have identified two compounds 5-bromo-2-(thiophene-2-carboxamido) benzoic acid (A) and ethyl 6-bromo-2-((dimethylamino)methyl)-5-hydroxy-1-phenyl-1H-indole-3-carboxylate(B) as best hits with allosteric mode of inhibition. FabG is an integral part of bacterial fatty acid biosynthetic system FAS II shown to be an essential gene in most ESKAPE Pathogens. The current work is focussed on lead expansion of these two hit molecules which ended up with forty-three analogues (twenty-nine analogues from lead compound A and fourteen compounds from lead compound B). The enzyme inhibition studies revealed that compound 15 (effective against EcFabG, AbFabG, StFabG, MtFabG1) and 19 (inhibiting EcFabG and StFabG) had potency of broad-spectrum inhibition on FabG panel.
- Varakala, Saiprasad Dasugari,Reshma, Rudraraju Srilakshmi,Schnell, Robert,Dharmarajan, Sriram
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- Synthesis of Polysubstituted Pyrroles through Electro-Oxidative Annulation of 1,3-Dicarbonyl Compounds and Primary Amines
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Reported herein is a synthetic method of polysubstituted pyrroles from easily available materials, 1,3-dicarbonyl compounds and primary amines, via electro-oxidative intermolecular annulation. Under similar conditions, enamines are also converted smoothly into desired products, indicating that in situ formed enamines are crucial intermediates for the first transformation. Neither transition-metal salts nor harsh conditions are required to facilitate the dehydrocyclization process.
- Xiong, Mingteng,Liang, Xiao,Zhou, Yifeng,Pan, Yuanjiang
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p. 4986 - 4993
(2021/04/12)
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- Nenitzescu Synthesis of 5-Hydroxyindoles with Zinc, Iron and Magnesium Salts in Cyclopentyl Methyl Ether
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In this work, mild Lewis acids and low environmental impact solvents were investigated for Nenitzescu synthesis. Cyclopentyl methyl ether can be used at room temperature in substitution of halogenated solvents with zinc, iron and magnesium salts as homogeneous catalysts to give 5-hydroxyindoles in fair to good yields. The reaction features a straightforward workup and excellent solvent recycle.
- Azzena, Ugo,Beccu, Andrea,Carboni, Silvia,Carraro, Massimo,De Luca, Lidia,Gaspa, Silvia,Livesi, Marco,Pira, Giovanni Michele,Pisano, Luisa,R?mer, Melina,Satta, Giuseppe,Solinas, Angelo,Usala, Elena
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supporting information
p. 5835 - 5842
(2021/11/17)
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- Photocatalytic Visible-Light-Induced Nitrogen Insertion via Dual C(sp3)-H and C(sp2)-H Bond Functionalization: Access to Privileged Imidazole-based Scaffolds
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Here we have demonstrated a visible-light-mediated metal-free organic-dye-catalyzed dehydrogenative N-insertion leading to highly substituted imidazoles and privileged dihydroisoquinoline-based imidazole derivatives via C(sp3)-H and C(sp2)-H bond functionalization. A sustainable, convenient, metal-free azidation/C-H aminative cyclization approach in the absence of stoichiometric oxidants is presented. This protocol involves a rare photoinduced iminyl radical as a key intermediate for the "N"insertion.
- Patel, Srilaxmi M.,P., Ermiya Prasad,Bakthadoss, Manickam,Sharada, Duddu S.
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supporting information
p. 257 - 261
(2021/01/15)
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- 5-Hydroxyindole-based EZH2 inhibitors assembled via TCCA-catalyzed condensation and Nenitzescu reactions
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5-Hydroxyindole derivatives have various demonstrated biological activities. Herein, we used 5-hydroxyindole as a synthetic starting point for structural alterations in a combinatorial process to synthesize 22 different compounds with EZH2 inhibitor pharmacophores. A series of 5-hydroxyindole-derived compounds were screened inhibitory activities against K562 cells. According to molecular modeling and in vitro biological activity assays, the preliminary structure-activity relationship was summarized. Compound L–04 improved both the H3K27Me3 reduction and antiproliferation parameters (IC50 = 52.6 μM). These findings revealed that compound L–04 is worthy of consideration as a lead compound to design more potent EZH2 inhibitors. During the preparation of compounds, we discovered that trichloroisocyanuric acid (TCCA) is a novel catalyst which demonstrates condensation-promoting effects. To gain insight into the reaction, in situ React IR technology was used to confirm the reactivity. Different amines were condensed in high yields with β-diketones or β-ketoesters in the presence of TCCA to afford the corresponding products in a short time (10~20 min), which displayed some advantages and provided an alternative condensation strategy.
- Chen, Guoliang,Du, Fangyu,Sun, Wenjiao,Wang, Lihui,Wu, Chunfu,Yang, Cheng,Zhou, Qifan
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supporting information
(2020/05/16)
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- β-Enaminone Synthesis from 1,3-Dicarbonyl Compounds and Aliphatic and Aromatic Amines Catalyzed by Iron Complexes of Fused Bicyclic Imidazo[1,5-a]pyridine Derived N-Heterocyclic Carbenes
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A series of Fe–NHC complexes (1–2)c of the fused bicyclic imidazo[1,5-a]pyridine framework of the type [CpFe(2-R-imidazo[1,5-a]pyridin-3-ylidene)(CO)2]BF4 {R = mesityl (1c), nPr (2c)} successfully carried out the synthesis of β-enamino ketones (3–10) and (17–27) and β-enamino esters (11–16) and (28–36) by the condensation of acyclic and cyclic 1,3-dicarbonyl compounds and various aliphatic and aromatic amines in the presence of light irradiation. Quite significantly, the catalytically relevant substrate adduct species of the type [CpFe(NHC)(acac)] (2e) and the product adduct species of the type [CpFe(NHC)(β-enaminone)] (2f) of the Fe–NHC precatalyst (2c) have been detected by mass spectrometry study. The [CpFe(2-R-imidazo[1,5-a]pyridin-3-ylidene)(CO)2]BF4 {R = mesityl (1c), nPr (2c)} complexes were obtained from their respective N–heterocyclic carbene precursors namely, the 2-R-imidazo[1,5-a]pyridin-2-ium chloride {R = mesityl (1a), nPr (2a)} by the reaction with CpFe(CO)2I in the presence of KN(SiMe3)2 followed by the salt metathesis reaction with AgBF4.
- Prakasham,Gangwar, Manoj Kumar,Ghosh, Prasenjit
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p. 295 - 313
(2019/01/24)
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- Citrus juice: Green and natural catalyst for the solvent-free silica supported synthesis of β-enaminones using grindstone technique
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Aim and Objective: Citrus Juice as an efficient, cost-effective and green catalyst employed for one-pot synthesis of various β-substituted enaminones through the reaction of β-dicarbonyl compounds with different primary amines in a solvent-free conditions on silica gel as solid surface using grindstone technique in high yields and short reaction times. The presented procedure is operationally simple, practical and green. Material and Methods: The wide application of this procedure is demonstrated by the use of various substituted amines to react with β-dicarbonyl compounds. The method was successfully applied for primary amines (15 entries) and the related enaminones were well synthesized in good to excellent yields. Melting points were measured on an Electro thermal 9100 apparatus. 1HNMR and 13C NMR spectra were recorded on a FTNMR BRUKER DRX 500 Avence spectrometer. Chemical shifts were given in ppm from TMS as internal references and CDCl3 was used as the solvent as well. The IR spectra were recorded on a Perkin Elmer FT-IR GX instrument. The chemicals used in this work were purchased from Merck and Fluka chemical companies. Results: Grinding synthesis of citrus juice catalyzed enamination of 1,3-dicarbonyls (acetylacetone, methyl and ethyl-3-oxobutanoate) with various primary amines (aromatic and aliphatic) under solvent-free silica supported conditions was examined and studied (15 entries) and the obtained enaminones were well synthesized in good to excellent yields. Furthermore, the effect of various catalysts on the yield and reaction time for grinding synthesis of 3-phenylamino-but-2-enoic acid ethyl ester (1) by this method has evaluated as well. Conclusion: a novel, efficient and green protocol for the grinding synthesis of enaminones using citrus juice as natural catalyst has been presented. This methodology is user friendly, green and low cost procedure under mild reaction condition with faster reaction rates. The citrus juice is inexpensive and non-toxic which makes the process convenient, more economic and benign. Furthermore, applying grindstone technique in solvent-free conditions, use of silica gel as a solid and heterogeneous surface in reaction, high yields of products, cleaner reaction profiles, and availability of the reagents makes this method a better choice for synthetic chemists.
- Marvi, Omid,Fekri, Leila Zare
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- Structural comparison of Mtb-DHFR and h-DHFR for design, synthesis and evaluation of selective non-pteridine analogues as antitubercular agents
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Tuberculosis is an infectious disease that affects millions of population every year. Mtb-DHFR is a validated target that is vital for nucleic acids biosynthesis and therefore DNA formation and cell replication. This paper report identification and synthesis of novel compounds for selective inhibition of Mtb-DHFR and unleash the selective structural features necessary to inhibit the same. Virtual screening of databases was carried out to identify novel compounds on the basis of difference between the binding pockets of the two proteins. Consensus docking was performed to improve upon the results and best ten hits were selected. Hit 1 was subjected to analogues design and the analogues were docked against Mtb-DHFR. From the docking results 11 compounds were selected for synthesis and biological assay against H37Rv. Most potent compound (IND-07) was tested for selectivity using enzymatic assay against Mtb-DHFR and h-DHFR. The compounds were found to have good inhibitory activity (25–200 μM) against H37Rv and in enzyme assay against Mtb-DHFR and h-DHFR the compound was found selective towards Mtb-DHFR with selectivity index of 6.53. This work helped to identify indole moiety as novel scaffold for development of novel selective Mtb-DHFR inhibitors as antimycobacterial agents.
- Sharma, Kalicharan,Tanwar, Omprakash,Sharma, Shweta,Ali, Shakir,Alam,Zaman,Akhter, Mymoona
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p. 319 - 333
(2018/07/25)
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- Evaluation of β-Aminocarboxylic Acid Derivatives in Hippocampal Excitatory Synaptic Transmission
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β-Aminocarboxylic acid derivatives (LINS04 series) were screened with the aim to explore their potential functional role in excitatory synaptic transmission in the central nervous system. We used field recordings in rat hippocampal slices to investigate the effects of the LINS04 series on the synaptic transmission at hippocampal CA1 synapses. We found that LINS04008 and LINS04009 increase the size of the evoked field excitatory postsynaptic potential (EPSP) in a dose-dependent manner. The concentration–response curve shows that the efficacy of LINS04008 is highest in the series (EC50 = 91.32 μM; maximum fEPSP 44.97%). The esters LINS04006 and LINS04005 did not affect the synaptic evoked activity. These data provide the first evidence of synaptic activity enhancement by these compounds and the importance of the acidic group to the activity. This set of data may provide direction for a strategic procedure to restore the glutamate synaptic transmission; however, further studies are needed to establish a more complete picture of how these molecules act on the glutamate transmission, which are in our mind for the next steps.
- Oliveira, Daniela R.,Luchez, Cibele V.,Bortolotto, Zuner A.,Fernandes, Jo?o P. S.
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- A new synthetic route to polyhydrogenated pyrrolo[3,4-b]pyrroles by the domino reaction of 3-bromopyrrole-2,5-diones with aminocrotonic acid esters
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A new synthetic approach to polyfunctional hexahydropyrrolo[3,4-b]pyrroles was developed based on cyclization of N-arylbromomaleimides with aminocrotonic acid esters. A highly chemo- and stereoselective reaction is a Hantzsch-type domino process, involving the steps of initial nucleophilic C-addition or substitution and subsequent intramolecular nucleophilic addition without recyclyzation of imide cycle.
- Shikhaliev, Khidmet,Sabynin, Artem,Sekirin, Valeri,Krysin, Michael,Zubkov, Fedor,Yankina, Kristina
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- Indole Based Weapons to Fight Antibiotic Resistance: A Structure-Activity Relationship Study
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Antibiotic resistance represents a worldwide concern, especially regarding the outbreak of methicillin-resistant Staphylococcus aureus, a common cause for serious skin and soft tissues infections. A major contributor to Staphylococcus aureus antibiotic resistance is the NorA efflux pump, which is able to extrude selected antibacterial drugs and biocides from the membrane, lowering their effective concentrations. Thus, the inhibition of NorA represents a promising and challenging strategy that would allow recycling of substrate antimicrobial agents. Among NorA inhibitors, the indole scaffold proved particularly effective and suitable for further optimization. In this study, some unexplored modifications on the indole scaffold are proposed. In particular, for the first time, substitutions at the C5 and N1 positions have been designed to give 48 compounds, which were synthesized and tested against norA-overexpressing S. aureus. Among them, 4 compounds have NorA IC50 values lower than 5.0 μM proving to be good efflux pump inhibitor (EPI) candidates. In addition, preliminary data on their ADME (absorption, distribution, metabolism, and excretion) profile is reported.
- Lepri, Susan,Buonerba, Federica,Goracci, Laura,Velilla, Irene,Ruzziconi, Renzo,Schindler, Bryan D.,Seo, Susan M.,Kaatz, Glenn W.,Cruciani, Gabriele
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p. 867 - 891
(2016/02/23)
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- Effect of solvent ratio and counter ions on the morphology of copper nanoparticles and their catalytic application in β-enaminone synthesis
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This work reports the synthesis of shape selective copper nanoparticles (NPs) using a microwave irradiation method, using diverse ratios of an ethylene glycol (EG)/water system. The solvent ratio of EG/water plays a pivotal role in the selective formation of CuO NPs. The alteration of the counter ion of the copper precursor leading to the selective synthesis of copper (CuO, Cu2O, Cu(OH)2) NPs has been observed. The synthesized copper NPs are well characterized using FEG-SEM, TEM, XRD, XPS, NH3-TPD and BET surface area. The prepared CuO NPs show high activity towards the synthesis of β-enaminones and β-enamino esters from 1,3 diketones and amines.
- Gajengi, Aravind L.,Sasaki, Takehiko,Bhanage, Bhalchandra M.
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p. 101800 - 101807
(2016/11/09)
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- Bimetallic Ag-Cu alloy nanoparticles as a highly active catalyst for the enamination of 1,3-dicarbonyl compounds
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Bimetallic nanoparticles, particularly those based on copper, have recently attracted a great deal of attention for the development of low cost and highly active catalysts due to the synergistic interaction between individual metal components. In this work, bimetallic Ag-Cu alloy nanoparticles were explored as a highly active and reusable catalyst for the enamination of 1,3-dicarbonyls using diverse amines. The nanocatalysts were intensively characterized by ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), high-resolution transmission electron microscopy-energy-dispersive spectroscopy (HRTEM-EDS) and valence band and core level X-ray photoelectron spectroscopy (XPS) to study the effect of the bimetallic structure and composition. In comparison to monometallic Ag and Cu nanoparticles, the alloyed Ag-Cu nanoparticles showed a high catalytic performance and the resultant catalytic activity was dependant on the Ag to Cu ratio. This enhanced catalytic activity should be related to the electronic interaction between Ag and Cu nanoparticles formed due to the intimate contact between them. Our study may serve as a foundation for designing efficient alloyed nanocatalysts for fine chemical synthesis via enamination reactions.
- Rout, Lipeeka,Kumar, Aniket,Dhaka, Rajendra S.,Dash, Priyabrat
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p. 49923 - 49940
(2016/06/15)
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- Three-component access to 2-pyrrolin-5-ones and their use in target-oriented and diversity-oriented synthesis
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The Hantzsch-type microwave-assisted, solvent-free sequential three-component reaction between primary amines, β-dicarbonyl compounds and α-bromoesters in the presence of indium trichloride afforded 2-pyrrolin-5-ones, which are difficult to access by alternative methods. Ready access to these compounds allowed their use as synthetic building blocks in a target-oriented project aimed at the synthesis of a compound that had previously been postulated as a candidate for HIV integrase inhibition on the basis of computational studies. The versatility of 2-pyrrolin-5-ones was further verified by their use in a diversity-oriented synthesis context, leading to a library of highly functionalized bispiro compounds. The overall process leading to these compounds involved the generation of six bonds and two cycles over three steps, two of which are multicomponent, and the fully controlled generation of up to four stereocenters, including two quaternary ones.
- Cores, ángel,Estévez, Verónica,Villacampa, Mercedes,Menéndez, J. Carlos
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p. 39433 - 39443
(2016/06/01)
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- Design of a graphene oxide-SnO2 nanocomposite with superior catalytic efficiency for the synthesis of β-enaminones and β-enaminoesters
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A graphene oxide (GO)-SnO2-based nanocomposite was synthesized by decorating the graphene oxide surface with SnO2 nanoparticles via a solvothermal process. The nanocomposite was characterized using Fourier transform infrared spectra (FTIR), FT-Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field-emission Scanning electron microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDS), Transmission electron microscopy (TEM) and N2 adsorption/desorption study. The FE-SEM and TEM images demonstrate the uniform distribution of the SnO2 nanoparticles on the GO surface and high-resolution transmission electron microscopy (HRTEM) confirms an average particle size of 8-12 nm. The GO-SnO2 nanocomposite has been found to be an extremely efficient catalyst for the synthesis of β-enaminones and β-enaminoesters in methanol solvent and also, in solventless conditions. The GO-SnO2 nanocomposites exhibited synergistically more superior catalytic efficiency compared to pure graphene oxide and SnO2 nanoparticles. The reaction conditions were optimized by changing different parameters such as catalyst, solvent, catalyst loading, and temperature. It has been found that the catalyst gave higher activity under solventless conditions than methanol. The GO-SnO2 composite was recycled for up to four cycles with minimal loss in activity.
- Kumar, Aniket,Rout, Lipeeka,Dhaka, Rajendra S.,Samal, Saroj L.,Dash, Priyabrat
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p. 39193 - 39204
(2015/05/20)
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- An efficient and convenient synthesis of 1,2,3-trisubstituted pyrroles via iodocyclization from ethyl acetoacetate
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A novel and efficient methodology for the synthesis of 1,2,3-trisubstituted pyrroles by one-pot two-step reaction has been developed. The iodocyclization of a series of β-enamino esters followed by dehydroiodination, led to the formation of corresponding pyrroles. This approach provides an easy access to a wide range of 1,2,3-trisubstituted pyrroles.
- Xu, Pengfei,Huang, Kunzhu,Liu, Zhiguo,Zhou, Ming,Zeng, Wenbin
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supporting information
p. 2929 - 2933
(2013/06/27)
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- Cu(TFA)2-catalyzed oxidative tandem cyclization/1,2-alkyl migration of enamino amides for synthesis of pyrrolin-4-ones
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A novel Cu(TFA)2-catalyzed oxidative tandem cyclization/1,2- alkyl migration of readily available enamino amides for the synthesis of pyrrolin-4-ones has been developed. The reaction tolerates a wide range of functional groups and is a reliable method for the rapid synthesis of substituted pyrrolin-4-ones in high yields under mild conditions.
- Zhang, Zhi-Jing,Ren, Zhi-Hui,Wang, Yao-Yu,Guan, Zheng-Hui
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supporting information
p. 4822 - 4825
(2013/10/08)
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- Sequential activation of σ-bonds: Intermolecular cascade annulation with migration and remote functionalization
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We demonstrate a new catalytic property of the lanthanide compound CeCl3.7H2O which sequentially activates N-H, sp 2 C-H and sp3 C-H σ-bonds at ambient temperature. The powerful catalyst enables selective C-C and C-N bond-forming intermolecular cascade annulation between enamines and diaryl-1,2-diketone to afford functionalized 3,3-diaryl-3-pyrrolin-2-ones involving migration of an aromatic ring. We have also initiated a new multicomponent strategy utilizing readily available and inexpensive precursors and environmentally benign CeCl 3.7H2O as an efficient catalyst under benign reaction conditions towards direct synthesis of several N-heterocycles including pentasubstituted 2-pyrrolinones and pyrroles. These observations provide new prospects and perspectives in σ-bond activation process for easy access to functional molecules.
- Dhara, Dipankar,Sengupta, Tista,Khamarui, Saikat,Ghosh, Sukla,Maiti, Dilip K.
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p. 1663 - 1673
(2014/01/17)
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- Ecofriendly and facile Nano ZnO catalyzed solvent-free enamination of 1,3-dicarbonyls
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Nano zinc oxide (Nano-ZnO) was explored as a reusable catalyst for the enamination of 1,3-dicarbonyls using diverse amines. To make the process environmentally viable, the reaction was carried out under solvent-free conditions and found to give good yield of desired products. The catalyst was characterized by various analytical techniques such as UV-spectroscopy, XRD, and TEM. The catalyst was found to be reusable up to four catalytic cycles without any appreciable loss in activity.
- Indulkar, Utkarsha U.,Kale, Sandip R.,Gawande, Manoj B.,Jayaram, Radha V.
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supporting information; experimental part
p. 3857 - 3860
(2012/08/27)
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- CeCl3·7H2O catalyzed C-C and C-N bond-forming cascade cyclization with subsequent side-chain functionalization and rearrangement: A domino approach to pentasubstituted pyrrole analogues
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CeCl3·7H2O is found as an efficient catalyst for new intermolecular domino reactions of three-, four- and seven-component assemblies of common precursors under benign reaction conditions. Generation of enaminioesters from β-keto esters and primary amines, activation of their allylic sp3 C-H, vinylic sp2 C-H and N-H bonds, multi C-C and C-N bond-forming cascade cyclization with 1,2-diketones and subsequent side-chain alkylation have been developed to construct functionalized pentasubstituted pyrroles and their chiral analogues. The scope of the domino reaction is successfully explored toward synthesis of highly aryl-substituted pyrroles, pentasubstituted pyrroles bearing C2-olefinic side-chain and spiro-2-pyrrolinones and their chiral analogues via unusual side-chain amination, elimination and ring contraction. The new domino reaction is operationally simple, robust, substrate specific, selective and high yielding.
- Dhara, Dipankar,Gayen, Krishnanka S.,Khamarui, Saikat,Pandit, Palash,Ghosh, Sukla,Maiti, Dilip K.
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p. 10441 - 10449
(2013/01/15)
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- A synthesis of functionalized dihydro-1H-pyrroles from Nef-isocyanide adducts and enamines
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α-Ketoimidoyl chlorides, obtained from α-addition of acyl chlorides onto alkyl isocyanides, are treated with enamines to afford 5-(alkylimino)-4-hydroxy-4,5-dihydro-1H-pyrrole-2,3,4-tricarboxylates and 2-(alkylimino)-3-hydroxy-2,3-dihydro-1H-pyrrole-3,4-dicarboxylates in good to excellent yields. Georg Thieme Verlag Stuttgart · New York.
- Yavari, Issa,Hosseinpour, Reza,Pashazadeh, Ramin
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experimental part
p. 1662 - 1666
(2012/08/13)
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- Silica sulfuric acid-mediated synthesis of β-enaminones and β-enaminoesters under microwave irradiation
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Silica sulfuric acid, a heterogeneous reagent, has been found to be an efficient catalyst for the synthesis of β-enaminones and β-enaminoesters under microwave irradiation in a microwave reactor within 2 min. The experimental procedure is simple and environment-friendly, and results in excellent yields of the products. Further, the catalyst is recyclable, and the reaction is 60 times faster than the reaction at room temperature. Copyright Taylor & Francis Group, LLC.
- Datta, Bandita,Pasha
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experimental part
p. 171 - 177
(2011/04/22)
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- Cyanuric chloride catalysed rapid conversion of β-ketoesters into β-enaminoesters under mild and solvent-free conditions
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Cyanuric chloride is shown to be an extremely efficient catalyst for the synthesis of β-enaminoesters from β-ketoesters under solvent-free conditions by grinding in a mortar with pestle at 25 °C. A short reaction time, an inexpensive and easily available catalyst, mild reaction conditions and excellent yields of the products are attractive features of this methodology.
- Kamble,Joshi,Atkore
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experimental part
p. 616 - 621
(2012/07/03)
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- Stereodefined homopropargyl amines by tandem nucleophilic addition/fragmentation of dihydropyridone triflates
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Dihydropyridone (DHPD) triflates undergo nucleophile-triggered fragmentation to provide homopropargyl amine derivatives, the stereochemistry of which is defined by starting from readily available β-amino esters.
- Tummatorn, Jumreang,Dudley, Gregory B.
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supporting information; experimental part
p. 158 - 160
(2011/03/20)
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- Solvent-free synthesis of β-enamino compounds promoted by Ferric(III) ammonium nitrate
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A variety of β-enamino esters and β-enaminones can be synthesized by the reaction of 1,3-dicarbonyl compounds and various primary amines in the presence of catalytic amount of ferric(III) ammonium nitrate at room temperature. This method is simple, requires short reaction times, high yield and the reaction proceeds under solvent-free conditions.
- Murthy,Venu,Govindh,Diwakar,Nagalakshmi,Singh
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experimental part
p. 3047 - 3053
(2010/11/04)
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- Silica-supported LiHSO4 as a highly efficient, heterogeneous and reusable catalytic system for the solvent-free synthesis of β-enaminones and β-enamino esters
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A highly efficient, simple and green procedure for the synthesis of β-enaminones and β-enamino esters is described. The reaction of aromatic and aliphatic amines with β-dicarbonyl compounds using catalytic amount of silica-supported LiHSO4 (LiHSO4/SiO2) under solvent-free conditions at 80 °C affords the title compounds in high to excellent yields and in short reaction times.
- Hasaninejad,Zare,Mohammadizadeh,Shekouhy
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experimental part
p. 69 - 76
(2010/10/21)
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- B2O3/Al2O3 as a new, highly efficient and reusable heterogeneous catalyst for the selective synthesis of β-enamino ketones and esters under solvent-free conditions
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Boron oxide adsorbed on alumina (B2O3/Al 2O3) has been found to be a new and highly efficient heterogeneous catalyst for the synthesis of β-enamino ketones and esters by the enamination of various primary and secondary amines with β-dicarbonyl compounds under solvent-free conditions. The important features of this methodology are broad substrate scope, high yield, no requirement of metal catalysts, high regio-and chemoselectivity and environmental friendliness. In addition, the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity.
- Chen, Jiu-Xi,Zhang, Chang-Fu,Gao, Wen-Xia,Jin, Hui-Le,Ding, Jin-Chang,Wu, Hua-Yue
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experimental part
p. 1552 - 1556
(2010/11/16)
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- Synthesis of pyrimido[6,1-a]isoquinolines via a one-pot, four-component reaction
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An efficient one-pot synthesis of pyrimido[6,1-a]isoquinoline-1-carboxylate derivatives is described. This involves the four-component reaction between primary amines, alkyl acetoacetates, isoquinoline and trichloromethylchloroformate (diphosgene) under mild conditions at ambient temperature. A facile and direct synthetic entry to pyrimido[6,1-a]isoquinolines via a one-pot, four-component reaction of primary amines and alkyl acetoacetates, isoquinoline and trichloromethylchloroformate (diphosgene) under mild conditions at ambient temperature is reported.
- Alizadeh, Abdolali,Rezvanian, Atieh,Zhu, Log-Guan
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experimental part
p. 6924 - 6927
(2010/09/18)
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- Expedient, one-pot preparation of fused indoles via CAN-catalyzed three-component domino sequences and their transformation into polyheterocyclic compounds containing pyrrolo[1,2-a]azepine fragments
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The CAN-catalyzed three-component between reaction between primary amines, β-dicarbonyl compounds and naphthoquinones or 2-bromonaphthoquinones afforded, respectively, 5-hydroxybenzo[g]indoles and benzo[f]indole-4,9-diones, the former of which were transformed into tetracyclic azepino[1,2-a]benzo[g] indole systems through a γ-alkylation/ring-closing metathesis sequence. The Royal Society of Chemistry 2010.
- Suryavanshi, Padmakar A.,Sridharan, Vellaisamy,Menendez, J. Carlos
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experimental part
p. 3426 - 3436
(2010/08/21)
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- Silver nanoparticles as an efficient, heterogeneous and recyclable catalyst for synthesis of β-enaminones
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A simple and efficient protocol has been developed for synthesis of β-enaminones and β-enamino esters catalyzed by silver nanoparticles as a novel, heterogeneous, moisture stable and recyclable catalyst under mild reaction conditions. The reaction was optimized with respect to various parameters such as catalyst screening, catalyst loading, different solvents and temperature. The silver nanoparticle exhibited excellent activity and the methodology is applicable to diverse substrates providing good to excellent yields of desired products. The catalyst was recycled for three consecutive cycles without any significant loss in activity.
- Bhatte, Kushal D.,Tambade, Pawan J.,Dhake, Kishor P.,Bhanage, Bhalchandra M.
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experimental part
p. 1233 - 1237
(2011/01/03)
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- An efficient synthesis of vinylogous carbamates from alkyl azides
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An efficient one-pot synthesis of vinylogous carbamates is reported starting from alkyl azides by using NH4Cl/Zn dust.
- Prabhakar, Akundi Surya,Sashikanth, Suthrapu,Reddy, Padi Pratap,Cherukupally, Praveen
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p. 8709 - 8711
(2008/03/14)
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- Heterocycle formation through aza-annulation: A stereochemically controlled route to (±)-lupinine
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The aza-annulation of an acyclic β-enaminoester with acryloyl chloride was found to be a very efficient method for nitrogen heterocycle formation. Stereospecific hydrogenation of the unsaturated dihydropyridone generated from aza-annulation gave a single disubstituted lactam product. The cis stereochemical relationship of the substituents was confirmed by transformation of the lactam to (±)-lupinine.
- Paulvannan,Schwarz,Stille
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p. 215 - 218
(2007/10/02)
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- Reaction of Maleimides and Ethyl 3-Aminocrotonates. A Reinvestigation Leading to an Improved Synthesis of Pyrrolopyridines
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Conditions employed for the reaction between maleimides and ethyl aminocrotonates were shown to yield pyrrolopyridines rather than the previously reported pyrrolopyrroles.
- Shah, Kanhaiya R.,Blanton, C. DeWitt
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p. 502 - 508
(2007/10/02)
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