Dehydrogenative Lactonization of Diols in Aqueous Media Catalyzed by a Water-Soluble Iridium Complex Bearing a Functional Bipyridine Ligand

Authors

  • Dr. Ken-ichi Fujita,

    Corresponding author
    1. Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku Kyoto 606-8501 (Japan), Fax: (+81) 75-753-6634
    • Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku Kyoto 606-8501 (Japan), Fax: (+81) 75-753-6634

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  • Wataru Ito,

    1. Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku Kyoto 606-8501 (Japan), Fax: (+81) 75-753-6634
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  • Prof. Dr. Ryohei Yamaguchi

    Corresponding author
    1. Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku Kyoto 606-8501 (Japan), Fax: (+81) 75-753-6634
    • Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku Kyoto 606-8501 (Japan), Fax: (+81) 75-753-6634

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Abstract

A new catalytic system for the dehydrogenative lactonization of a variety of benzylic and aliphatic diols in aqueous media was developed. By using a water-soluble, dicationic iridium catalyst bearing 6,6′-dihydroxy-2,2′-bipyridine as a functional ligand, highly atom economical and environmentally benign synthesis of various lactones was achieved in good to excellent yields. Recovery and reuse of the catalyst were also accomplished by a simple phase separation and the recovered catalyst maintained its high activity at least until the fifth run.

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