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.

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.…