Get access

An N-Heterocyclic Carbene/Lewis Acid Strategy for the Stereoselective Synthesis of Spirooxindole Lactones

Authors

  • Dr. Julien Dugal-Tessier,

    1. Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (USA)
    Search for more papers by this author
  • Dr. Elizabeth A. O'Bryan,

    1. Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (USA)
    Search for more papers by this author
  • Thomas B. H. Schroeder,

    1. Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (USA)
    Search for more papers by this author
  • Daniel T. Cohen,

    1. Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (USA)
    Search for more papers by this author
  • Prof. Karl A. Scheidt

    Corresponding author
    1. Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (USA)
    • Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (USA)
    Search for more papers by this author

  • Financial support has been generously provided by the NIH (NIGMS RO1-GM073072). T.B.H.S. was supported by a 2011 Northwestern Summer Undergraduate Research Grant. D.T.C thanks the ACS Division of Organic Chemistry for a 2011-12 Graduate Fellowship (sponsored by Organic Synthesis/Organic Reactions). We thank Michael Katz (NU) and John M. Roberts (NU) for assistance with X-ray crystallography.

Abstract

original image

A cooperative catalysis approach for the enantioselective formal [3+2] addition of α,β-unsaturated aldehydes to isatins has been developed. Homoenolate annulations of β-aryl enals catalyzed by an N-heterocyclic carbene (NHC) require the addition of lithium chloride for high levels of enantioselectivity. This NHC-catalyzed annulation has been used for the total synthesis of maremycin B.

Ancillary