Asymmetric Iminium Ion Catalysis: An Efficient Enantioselective Synthesis of Pyranonaphthoquinones and β-Lapachones

Authors

  • Magnus Rueping Prof. Dr.,

    1. Degussa Endowed Professorship, Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University Frankfurt am Main, Max-von-Laue Strasse 7, 60438 Frankfurt am Main, Germany, Fax: (+49) 69-798-29248
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  • Erli Sugiono Dr.,

    1. Degussa Endowed Professorship, Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University Frankfurt am Main, Max-von-Laue Strasse 7, 60438 Frankfurt am Main, Germany, Fax: (+49) 69-798-29248
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  • Estíbaliz Merino Dr.

    1. Degussa Endowed Professorship, Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University Frankfurt am Main, Max-von-Laue Strasse 7, 60438 Frankfurt am Main, Germany, Fax: (+49) 69-798-29248
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  • The authors acknowledge Degussa GmbH and the DFG (Priority Programme Organocatalysis) for financial support as well the Ministerio de Educacion y Ciencia, Spain, for a stipend given to E.M. and Dr. M. Bolte for the X-ray crystal structure analysis.

Abstract

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An addition–cyclization reaction cascade triggered by an organocatalyst was used for the enantioselective preparation of a series of biologically active 1,2- and 1,4-pyranonaphthoquinones from aliphatic and aromatic α,β-unsaturated aldehydes and 2-hydroxy-1-4-naphthoquinone. A trimethylsilyl-protected diarylprolinol serves as the Lewis base organocatalyst.

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