• 제목/요약/키워드: palladium catalyst

검색결과 133건 처리시간 0.019초

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

  • 함원훈;양재권;임태균
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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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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Preparation of Nanosized Palladium-Graphene Composites and Photocatalytic Degradation of Various Organic Dyes

  • Kim, Jae Jin;Ko, Weon Bae
    • Elastomers and Composites
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    • 제51권1호
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    • pp.10-16
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    • 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.

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

  • 박상호;정문영;배진영
    • 폴리머
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    • 제31권6호
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    • pp.469-473
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    • 2007
  • 본 연구에서는 OTFT의 유기물 반도체 층으로 쓰일 수 있는 oligo(3-methylthiothiophene)를 전이금속 촉매인 palladium 촉매를 이용한 커플링 중합법을 이용하여 합성하였다. Thiophene 올리고머의 단량체를 합성하기 위해서 metal halogen exchange reaction에 의하여 3-methylthiothiophene를 합성하였고, thiophene 구조의 2, 5번의 위치에 brome기를 도입함으로써 최종적으로 2,5-dibromo-3-methylthiothiophene를 합성하였다. 합성된 단량체와 올리고머는 $^1H-NMR$, ATR 분석을 통하여 그 구조를 확인하였으며, TGA로 열적 안정성을 관찰하였고 진공 증착법(thermal evaporation)을 이용하여 기판상에 증착시켜 OTFT 소재로서의 적용 가능성을 확인하였다.

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
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    • 제34권4호
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    • pp.1127-1130
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    • 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
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    • 제34권9호
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    • pp.2645-2649
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    • 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
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    • 제31권8호
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    • pp.2195-2200
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    • 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.