- 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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- 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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p. 73612 - 73618
(2015/09/15)
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- Cu(OAc)2/TFA-promoted formal [3 + 3] cycloaddition/oxidation of enamines and enones for synthesis of multisubstituted aromatic amines
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New strategies for the oxidative cycloaddition of enones with enamines are developed. These cycloaddition reactions directly afford substituted aromatic amines, which are important in organic chemistry, in moderate to good yield. Cu(OAc)2/TFA is shown to be essential to achieve high reaction efficiency.
- Li, Liang,Zhao, Mi-Na,Ren, Zhi-Hui,Li, Jian-Li,Guan, Zheng-Hui
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supporting information; experimental part
p. 3506 - 3509
(2012/08/08)
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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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- A pairwise chemical genetic screen identifies new inhibitors of glucose transport
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Oxidative phosphorylation (OXPHOS) and glycolysis are the two main pathways that control energy metabolism of a cell. The Warburg effect, in which glycolysis remains active even under aerobic conditions, is considered a key driver for cancer cell proliferation, malignancy, metastasis, and therapeutic resistance. To target aerobic glycolysis, we exploited the complementary roles of OXPHOS and glycolysis in ATP synthesis as the basis for a chemical genetic screen, enabling rapid identification of novel small-molecule inhibitors of facilitative glucose transport. Blocking mitochondrial electron transport with antimycin A or leucascandrolide A had little effect on highly glycolytic A549 lung carcinoma cells, but adding known glycolytic inhibitors 2-deoxy-D-glucose, iodoacetate or cytochalasin B, rapidly depleted intracellular ATP, displaying chemical synthetic lethality. Based on this principle, we exposed antimycin A-treated A549 cells to a newly synthesized 955 member diverse scaffold small-molecule library, screening for compounds that rapidly depleted ATP levels. Two compounds potently suppressed ATP synthesis, induced G1 cell-cycle arrest and inhibited lactate production. Pathway analysis revealed that these novel probes inhibited GLUT family of facilitative transmembrane transporters but, unlike cytochalasin B, had no effect on the actin cytoskeleton. Our work illustrated the utility of a pairwise chemical genetic screen for discovery of novel chemical probes, which would be useful not only to study the system-level organization of energy metabolism but could also facilitate development of drugs targeting upregulation of aerobic glycolysis in cancer.
- Ulanovskaya, Olesya A.,Cui, Jiayue,Kron, Stephen J.,Kozmin, Sergey A.
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experimental part
p. 222 - 230
(2011/10/08)
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- Ni(OAc)2: A highly efficient catalyst for the synthesis of enaminone and enamino ester derivatives under solvent-free conditions
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Ni(OAc)2 was found to be an efficient catalyst for the synthesis of β-enamino ketones or esters from β-dicarbonyl compounds and amines under solvent-free conditions. The reusability of the catalyst was successfully examined without noticeable loss of its catalytic activity. Copyright
- Liu, Ju-Yan,Cao, Gai-E.,Xu, Wei,Cao, Jie,Wang, Wei-Lu
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experimental part
p. 685 - 691
(2010/11/20)
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- One-Pot synthesis of -alkylidene - Butyrolacton-2-ones (Tetronic Acid Derivatives): Polar solvent induces a new type of -lactonization
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An efficient, one-pot synthetic protocol toward α-alkylidene γ- butyrolacton-2-ones, a rather unexplored class of heterocyclic scaffolds starting from primary amines, methyl acetoacetate, and chloroacetyl chloride is described. The mixture of MeCN-MeOH as a polar solvent triggers a new cycloaddition of the enaminone intermediate. The reaction is completed within 12 hours under reflux condition to produce the title compounds. Georg Thieme Verlag Stuttgart.
- Alizadeh, Abdolali,Sabahnoo, Hamideh,Noaparast, Zohreh,Zohreh, Nasrin,Mikaeili, Azadeh
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experimental part
p. 1854 - 1858
(2010/10/04)
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- Simple and efficient synthesis of 3-aminopropenones and 3-aminopropenoates catalyzed by copper(II) nitrate trihydrate under solvent-free conditions
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A simple, efficient and environmentally begin method has been developed for the synthesis of 3-aminopropenones and 3-aminopropenoates through the reaction of 1,3-dicarbonyl compounds with amines in the presence of Cu(NO 3)2 · 3H2O under solvent-free conditions.
- Li, Geng-Chen
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experimental part
p. 789 - 792
(2009/09/29)
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