Urea- and Thiourea-Substituted Cinchona Alkaloid Derivatives as Highly Efficient Bifunctional Organocatalysts for the Asymmetric Addition of Malonate to Nitroalkenes: Inversion of Configuration at C9 Dramatically Improves Catalyst Performance.

Authors

  • Séamus H. McCooey,

    1. Centre for Synthesis and Chemical Biology, Department of Chemistry, Trinity College, University of Dublin, Dublin 2, Ireland, Fax: (+353) 1-671-2826
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  • Stephen J. Connon Dr.

    1. Centre for Synthesis and Chemical Biology, Department of Chemistry, Trinity College, University of Dublin, Dublin 2, Ireland, Fax: (+353) 1-671-2826
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  • Financial support from the Irish Research Council for Science Engineering and Technology is gratefully acknowledged. We would like to thank TopChem Laboratories Ltd. and the Gunnlaugsson group (TCD) for the use of their equipment.

Abstract

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Natural not always best: Novel N-aryl urea and thiourea derivatives of dihydrocinchona alkaloids serve as efficient catalysts for the asymmetric addition of dimethyl malonate to a range of nitroalkenes. Catalytic activity and selectivity depend strongly on the relative configuration at C8/C9. Catalysts with “non-natural” inverted configuration at C9 display excellent activity and enantioselectivity at loadings as low as 0.5 mol %.

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