InCl3-Mediated Addition of Indole to Isatogens: An Expeditious Synthesis of 13-deoxy-Isatisine A

Authors

  • Chepuri V. Suneel Kumar,

    1. Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008 (India), Fax: (+91) 20-25902629
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  • Dr. Vedavati G Puranik,

    1. Center for Material Characterization, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008 (India)
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  • Dr. Chepuri V. Ramana

    Corresponding author
    1. Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008 (India), Fax: (+91) 20-25902629
    • Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008 (India), Fax: (+91) 20-25902629
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Abstract

A strategy directed towards the total synthesis of isatisine A that involves several late-stage metal-catalyzed transformations that address the key carbon–carbon and carbon–heteroatom bond formations has been developed. As a part of this strategy, methods for the addition of indoles to isatogens that lead selectively to either 2,2-disubstituted N-hydroxyindolin-3-one or 2,2-disubstituted indolin-3-one compounds have been developed by employing InCl3 as a catalyst or as the reagent. The present methods provide the first examples of the additions of indoles to the isatogen nucleus. To demonstrate its viability, the synthesis of 13-deoxy-isatisine A has been completed in ten steps from a known and easily available lactone.

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