Preferential Formation of Cyclic Trimers by Palladium-Catalyzed Oxidative Coupling Reactions of 2,18-Diethynylporphyrins

Authors

  • Sumito Tokuji,

    1. Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
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  • Prof. Dr. Hideki Yorimitsu,

    Corresponding author
    1. Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
    • Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
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  • Prof. Dr. Atsuhiro Osuka

    Corresponding author
    1. Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
    • Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
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  • This work was supported by MEXT through Grants-in-Aid (Nos. 22245006 (A), 20108001 “pi-Space”, and 24106721 “Reaction Integration”). S.T. acknowledges a JSPS Fellowship for Young Scientists. We thank Prof. Dr. H. Maeda and Y. Bando of Ritsumeikan University for MALDI-TOF MS measurement.

Abstract

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And palladium makes three: In contrast to the formation of cyclic dimers in the Cu-mediated reaction, Pd-catalyzed oxidative coupling of 2,18-diethynylporphyrins preferentially produced cyclic trimers (see scheme). A porphyrin hexamer with a doubly 1,3-butadiyne-bridged conjugated trimeric core and directly meso-appended peripheral porphyrin substituents was also synthesized.

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