Chiral Calcium Iodide for Asymmetric Mannich-type Reactions of Malonates with Imines Providing β-Aminocarbonyl Compounds

Authors

  • Dr. Tetsu Tsubogo,

    1. Department of Chemistry, School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 (Japan), Fax: (+81) 3-5684-0634
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  • Shota Shimizu,

    1. Department of Chemistry, School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 (Japan), Fax: (+81) 3-5684-0634
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  • Prof. Dr. Shū Kobayashi

    Corresponding author
    1. Department of Chemistry, School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 (Japan), Fax: (+81) 3-5684-0634
    • Department of Chemistry, School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 (Japan), Fax: (+81) 3-5684-0634

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Abstract

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Out of the pybox: We have developed a novel chiral calcium iodide catalyst from CaI2 and a pybox that is stable under moisture and oxygen. This catalyst was applied to catalytic asymmetric Mannich-type reactions of malonates with both N-Boc-protected aromatic and aliphatic imines, and resulted in moderate to high yields with high enantioselectivities. To the best of our knowledge, this is the first example of highly enantioselective metal-catalyzed asymmetric Mannich-type reactions of malonates with N-Boc-protected aliphatic imines. The Mannich adduct was successfully converted into the α-hydroxy β-amino acid derivative. We have also shown the unique structure of the chiral Ca complexes with malonates.

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