• Title/Summary/Keyword: Coupling reactions

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Synthesis and Characterization of Graphene and Graphene Oxide Based Palladium Nanocomposites and Their Catalytic Applications in Carbon-Carbon Cross-Coupling Reactions

  • Lee, Minjae;Kim, Bo-Hyun;Lee, Yuna;Kim, Beom-Tae;Park, Joon B.
    • Bulletin of the Korean Chemical Society
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    • v.35 no.7
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    • pp.1979-1984
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    • 2014
  • We have developed an efficient method to generate highly active Pd and PdO nanoparticles (NPs) dispersed on graphene and graphene oxide (GO) by an impregnation method combined with thermal treatments in $H_2$ and $O_2$ gas flows, respectively. The Pd NPs supported on graphene (Pd/G) and the PdO NPs supported on GO (PdO/GO) demonstrated excellent carbon-carbon cross-coupling reactions under a solvent-free, environmentally-friendly condition. The morphological and chemical structures of PdO/GO and Pd/G were fully characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). We found that the remarkable reactivity of the Pd/G and PdO/GO catalysts toward the cross-coupling reaction is attributed to the high degree of dispersion of the Pd and PdO NPs while the oxidative states of Pd and the oxygen functionalities of graphene oxide are not critical for their catalytic performance.

Palladium-Catalyzed Coupling between Quinolone Moieties and Heteroacyl Stannes - Synthesis of C-7 Heteroacyl Quinolone Derivatives

  • 함원훈;양재권;임태균
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.221-221
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    • 1994
  • The cross-coupling reaction of organo tin reagents with a variety of organic halides, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. We use this method for antibacterial agents, and synthesis of new quinolone derivatives which have carbon-carbon bond at C-7 position of general quinolone moieties. Aryl tin, quinolone moieties, and palladium catalyst were refluxed in DMF to afford new quinolone derivatives. This palladium catalyzed coupling reactions have capacity for further synthetic elaboration.

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Heterogeneous Suzuki Cross-Coupling Reaction Catalyzed by Magnetically Recyclable Nanocatalyst

  • Choi, Kwang-Hyun;Shokouhimehr, Mohammadreza;Sung, Yung-Eun
    • Bulletin of the Korean Chemical Society
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    • v.34 no.5
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    • pp.1477-1480
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    • 2013
  • The Suzuki cross-coupling reactions proceeded in excellent yields when it was catalyzed by magnetically recyclable nanocatalyst. This nanocatalyst provided very high catalytic activity with low loading level (1 mol %), because the palladium nanoparticles were so small in size (~2 nm) and located on the surface of the nanocomposite. It was also easily recovered from the reaction mixture using a magnet and reused for six consecutive cycles.

Cross-Coupling Reaction of 2-halo1-methyl-1H-imidazo[4,5-b]pyridine Offers a New Synthetic Route to Mutagenic Heterocyclic Amine-PHIP and DMIP

  • Sajith, Ayyiliath M.;Muralidharan, Arayambath;Karuvalam, Ranjith P.;Haridas, Karickal R.
    • Journal of the Korean Chemical Society
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    • v.57 no.3
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    • pp.361-364
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    • 2013
  • A modified synthetic approach to the synthesis of heterocyclic food mutagens, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PHIP) and 2-amino-1,6-dimethylimidazo[4,5-b]pyridine (DMIP) is reported. This route highlights an optimized palladium catalysed Buchwald cross-coupling of 2-halo-1-methyl-imidazo[4,5-b]pyridine with benzophenoneimine followed by acidic hydrolysis to yield compound 7. Using finely tailored conditions, Suzuki cross-coupling reactions with highly efficient catalytic systems were performed as the final step on 8 to introduce the aryl group and methyl group on the heterocyclic core.

Fe(HSO4)3 as an Efficient Catalyst for Diazotization and Diazo Coupling Reactions

  • Rahimizadeh, Mohammad;Eshghi, Hossein;Shiri, Ali;Ghadamyari, Zohreh;Matin, Maryam M.;Oroojalian, Fatemeh;Pordeli, Parvaneh
    • Journal of the Korean Chemical Society
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    • v.56 no.6
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    • pp.716-719
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    • 2012
  • Diazo coupling reactions of aromatic amines with 2-naphthol in a green, efficient and easy procedure is described. Ferric hydrogensulfate catalyses this reaction in water at room temperature and short reaction time with high yields. The antibacterial activities of the synthesized compounds against four pathogenic bacteria are also investigated.

Synthesis of 3,4,5-Trisubstituted Isoxazoles through Gold-Catalyzed Cascade Cyclization-Oxidative Alkynylation and Cyclization-Fluorination of 2-Alkynone O-Methyloximes

  • Song, Doo-Hee;Ryu, Jae-Sang
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2635-2644
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    • 2014
  • Gold-catalyzed tandem cyclization-oxidative alkynylation and cyclization-fluorination reactions of 2-alkynone O-methyloximes are described. The reactions proceed smoothly at room temperature in the presence of 10 mol % of $(PPh_3)AuNTf_2$, 2.5 equivalents of selectfluor, and 2 equivalents of $K_3PO_4$. 2-Alkynone O-methyloximes undergo intramolecular oxyauration/cyclization and ensuing oxidative cross-coupling and fluorination process to afford the corresponding 3,4,5-trisubstituted isoxazoles in a cascade manner.

A NOTE ON THE CAUCHY PROBLEM FOR HEAT EQUATIONS WITH COUPLING MOVING REACTIONS OF MIXED TYPE

  • LIU, BINGCHEN;LI, FENGJIE
    • Journal of applied mathematics & informatics
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    • v.34 no.5_6
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    • pp.359-367
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    • 2016
  • This paper deals with the Cauchy problem for heat equations with coupling moving reactions of mixed type. After obtaining the infinite Fujita blow-up exponent, we classify optimally the simultaneous and non-simultaneous blow-up for two components of the solutions. Moreover, blow-up rates and set are determined. By using the analogous procedures, one can fill in the gaps for the other two systems, which are studied in the paper 'Australian and New Zealand Industrial and Applied Mathematics Journal' 48(2006)37-56.