• Title/Summary/Keyword: sonogashira

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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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Preparation, Characterization, and Catalytic Applications of Graphene-palladium Nanocomposites

  • Hong, Yeong-Guk;Yu, Se-Hui;Park, Jun-Beom
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.262-262
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    • 2012

  • Modifications of graphenes have been studied for catalytic applications due to their advantages such as high surface area, conductivity and thermal stability. In this research, individual graphene oxide (GO) sheets were exfoliated from graphite using Hummers and Offeman method. Pd nano-particles were deposited on the GO surface using Pd2+ ion exchange where hydroxyl groups on the GO act as nucleation sites of Pd nanoparticles and their dispersions. The thermal treatments of the Pd-GO in H2 flow produced Pd-Graphene nanocomposites. Their catalytic performances in Sonogashira reaction were investigated. Morphological and chemical structures of the GO, Pd-GO, and Pd-Graphene were investigated using FT-IR, XRD, TEM, STEM, and XPS. The catalytic performances have been investigated using microwave reactor.

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