• Title/Summary/Keyword: Palladium catalyst

Search Result 133, Processing Time 0.018 seconds

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
    • /
    • 1994.04a
    • /
    • pp.221-221
    • /
    • 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.

  • PDF

Preparation of Nanosized Palladium-Graphene Composites and Photocatalytic Degradation of Various Organic Dyes

  • Kim, Jae Jin;Ko, Weon Bae
    • Elastomers and Composites
    • /
    • v.51 no.1
    • /
    • pp.10-16
    • /
    • 2016
  • Nanosized palladium particles were synthesized using palladium(II) chloride, trisodium citrate dihydrate, and sodium borohydride under stirring condition. Nanosized palladium-graphene composites were prepared from palladium nanoparticles, and graphene was enclosed with polyallylamine under stirring condition for 1 h followed by ultrasonication for 3 h. Nanosized palladium-graphene composites were heated in an electric furnace at $700^{\circ}C$ for 2 h and characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. UV-vis spectrophotometry was used to evaluate the nanosized palladium-graphene composites as a catalyst in the photocatalytic degradation of various organic dyes such as methylene blue, methyl orange, rhodamine B, and brilliant green under ultraviolet light at 254 nm.

Synthesis and Application of Oligo(3-Methylthiothiophene) Using Palladium Catalyst (Palladium 촉매를 이용한 Oligo(3-methylthiothiophene)의 합성과 응용)

  • Park, Sang-Ho;Jung, Moon-Young;Bae, Jin-Young
    • Polymer(Korea)
    • /
    • v.31 no.6
    • /
    • pp.469-473
    • /
    • 2007
  • In this study, oligo(3-methylthiothiophene) was synthesized from thiophene derivative according to the method of reductive coupling using palladium catalyst. For the preparation of monomer, 3-methylthiothiophene was first synthesized through the metal-halogen exchange reaction of 3-bromothiophene with n-butyllithiuim, and the corresponding 2,5-dibromo-3-methylthiothiophene was formed by bromination. Their synthesis and characterization were determined by $^1H-NMR$ and ATR analyses. Thermal stability of the oligothiophene was monitored by thermogravimetric analysis (TGA). Thermal evaporation of the oligo(3-methylthiothiophene) on the substrate was attempted for OTFT applications.

Submicrospheres as Both a Template and the Catalyst Source. Silica Submicro-reactor Dotted with Palladium Nanoparticles as Catalysts

  • Kim, Sung Min;Noh, Tae Hwan;Jung, Ok-Sang
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.4
    • /
    • pp.1127-1130
    • /
    • 2013
  • Formation of the monodisperse submicrospheres consisting of ionic palladium(II) complexes, $[(Me_4en)Pd(L)]_2(X)_4$($Me_4en$ = N,N,N',N'-tetramethylethylenediamine; L = bis(4-(4-pyridylcarboxyl)phenyl)methane; $X^-=BF_4{^-}$ and $ClO_4{^-}$), has been carried out without any templates or additives. The submicrospheres were coated with silicates, and then calcined in air at $550^{\circ}C$ for 1 h, to efficiently form hollow-spherical $SiO_2$ submicro-reactors dotted with palladium(0) nanoparticles (PdNPs). That is, the submicrospheres act as both a template and a source of the palladium metal nanoparticles. The submicro-reactors containing nano-catalysts have been characterized by means of SEM, TEM, and XPS. Notably, the reactors were proved to be very effective for Suzuki-Miyaura cross-coupling and hydrogenation reactions.

Synthesis of 2-Substituted Benzofurans from o-Iodophenols and Terminal Alkynes with a Recyclable Palladium Catalyst Supported on Nano-sized Carbon Balls under Copper- and Ligand-Free Conditions

  • Yum, Eul Kgun;Yang, Ok-Kyung;Kim, Ji-Eun;Park, Hee Jung
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.9
    • /
    • pp.2645-2649
    • /
    • 2013
  • We have developed a one-step synthesis of benzofurans from o-iodophenol and various terminal alkynes, by using Pd catalyst supported on nano-sized carbon balls (NCB) under copper- and ligand free conditions. This recyclable catalyst could be reused more than 5 times in the same heteroannulation reaction. The results have demonstrated that diverse 2-substituted benzofurans with tolerant functional groups can be prepared simply and conveniently under these conditions.

Palladium Nanoparticles Suspended in an Ionic Liquid as Reusable Catalyst for Alkyne Semihydrogenation

  • Lee, Jin-Kyu;Kim, Dae-Won;Cheong, Min-Serk;Lee, Hyun-Joo;Cho, Byung-Won;Kim, Hoon-Sik;Mukherjee, DebKumar
    • Bulletin of the Korean Chemical Society
    • /
    • v.31 no.8
    • /
    • pp.2195-2200
    • /
    • 2010
  • The reaction of $PdCl_2$ dispersed in tetra-n-butylammonium bromide with tributyl amine at $120^{\circ}C$ under argon leads to stable isolable nanometric particles. X-ray diffraction analysis of the material indicated that it is constituted of Pd(0). Transmission electron microscopy analysis of the particles dispersed in acetone shows the mean particle size distribution ($4{\pm}1\;nm$). The isolated palladium nanoparticles can be dispersed in an ionic liquid or in methanol or used in solventless condition for selective hydrogenation of 2-hexyne under mild reaction conditions(0.2 MPa and $20^{\circ}C$). The commercial variety of the Lindlar catalyst was also studied for comparative investigations.