• Title/Summary/Keyword: Sonogashira coupling

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Facile Synthesis of Natural Moracin Compounds using Pd(OAc)2/P(tBu)3-HBF4 as a Sonogashira Coupling Reagent

  • Lee, Jae Jun;Yun, So-Ra;Jun, Jong-Gab
    • Bulletin of the Korean Chemical Society
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    • v.35 no.12
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    • pp.3453-3458
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    • 2014

  • An efficient and practical synthesis of natural moracins, which have diverse range of biological properties including anticancer, antioxidant, and antibacterial activities, has been achieved using $Pd(OAc)_2/P(^tBu)_3-HBF_4$ as a Sonogashira coupling reagent which solved the unreactive problems in case of higher electron density of haloaryl compounds in the reaction. Lowering electron density of halophenol with acetylation and changing Sonogashira coupling reagent from $PdCl_2(PPh_3)_2$ to $Pd(OAc)_2/P(^tBu)_3-HBF_4$ smoothly produce the benzofuran structures in the syntheses of moracins M, N and S. The electron deficient halobenzaldehyde, however, easily forms the benzofuran using original Sonogashira conditions, and utilized for the first synthesis of moracin Y.

  • https://doi.org/10.5012/bkcs.2014.35.12.3453 인용 PDF KSCI

High Catalytic Activity and Recyclability of Graphene Oxide Based Palladium Nanocomposites in Sonogashira Reaction

  • Kim, Bo Hyun;Park, Joon B.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.139.1-139.1
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    • 2013

  • Graphene and graphene oxide (GO) have been modified with palladium nanoparticles (Pd NPs) to develop high performance catalysts for the Sonogashira cross coupling reaction. To understand catalytic performance of Pd NPs on graphene (Pd/G) and Pd NPs on GO (Pd/GO), we monitored their morphological and electronic structural changes before/after Sonogashira reaction using FT-IR, XRD, XPS, and XAFS. Here, we demonstrate that both Pd/G and Pd/GO show high catalytic efficiency toward the Sonogashira reaction, but only Pd/GO revealed excellent recyclability. The remarkable catalytic efficiency of both catalysts is attributed to the high degree of the Pd NP dispersions on supports and thus smaller Pd NPs can provide highly reactive low coordinated Pd atoms. However, we attributed the excellent recyclability of Pd/GO to the presence of oxygen functionalities on GO, which can provide nucleation sites for the detached Pd atoms during the Sonogashira reaction and prevent agglomeration of the Pd NPs since the oxygen functional groups are very reactive to mobile Pd adatoms.

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Solution Processable Symmetric 4-Alkylethynylbenzene End-Capped Anthracene Derivatives

  • Jang, Sang-Hun;Kim, Hyun-Jin;Hwang, Min-Ji;Jeong, Eun-Bin;Yun, Hui-Jun;Lee, Dong-Hoon;Kim, Yun-Hi;Park, Chan-Eon;Yoon, Yong-Jin;Kwon, Soon-Ki;Lee, Sang-Gyeong
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.541-548
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    • 2012

  • New candidates composed of anthracene and 4-alkylethynylbenzene end-capped oligomers for OTFTs were synthesized under Sonogashira coupling reaction conditions. All oligomers were characterized by FT-IR, mass, UV-visible, and PL emission spectrum analyses, cyclic voltammetry (CV), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), $^1H$-NMR, and $^{13}C$-NMR. Investigation of their physical properties showed that the oligomers had high oxidation potential and thermal stability. Thin films of DHPEAnt and DDPEAnt were characterized by spin coating them onto Si/$SiO_2$ to fabricate top-contact OTFTs. The devices prepared using DHPEAnt and DDPEAnt showed hole field-effect mobilities of $4.0{\times}10^{-3}cm^2$/Vs and $2.0{\times}10^{-3}cm^2$/Vs, respectively, for solution-processed OTFTs.

  • https://doi.org/10.5012/bkcs.2012.33.2.541 인용 PDF KSCI

Preparation of Graphene Based PdOx and CuOx/MnOx Nanocomposites and Their Catalytic Applications in C-C Coupling and CH3SH Decomposition Reactions

  • Lee, Gyeong-Hun;Park, Jun-Beom
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.175.2-175.2
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    • 2014

  • Graphene (G) has been modified with palladium, copper, and manganese oxide nanoparticles (NPs), and their catalytic applications have been studied in C-C coupling reactions and methylmercaptan (CH3SH) decomposition reactions. In this research, graphite oxide (GO) sheets were exfoliated and oxidized from graphite powder and impregnated with metal precursors including Pd2+, Cu2+, and Mn2+. The thermal treatments of the metal impregnated GO in preferred gas environments produced Pd NPs on graphene (Pd/G), PdO NPs on GO (PdO/GO), and CuOx and MnOx NPs on graphene (CuOx/MnOx/G). In case of Pd/G and PdO/GO, the TEM images show that, although the mean size of the Pd NPs changed significantly before and after the C-C coupling reaction, that of the PdO NPs didn't, implying that the PdO/GO was superior to Pd/G in terms of the recyclability. Also, we demonstrate that the CuOx/MnOx/G exerts the excellent catalytic efficiency in CH3SH decomposition reaction comparing with conventional catalysts. The chemical and electronic structural changes were investigated using XRD and XPS.

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