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.

Abstract

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 %. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2005/z501721_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.