Novel 1,4-Diphosphanes with Imidazolidin-2-one Backbones as Chiral Ligands: Highly Enantioselective Rh-Catalyzed Hydrogenation of Enamides

Abstract

Appropriate gauche steric interactions between the N-substituents and the phosphanylmethyl groups (see picture, top right) in the novel 1,4-diphosphane ligands 1 having an imidazolidin-2-one backbone affect the conformational flexibility of the seven-membered chelate ring formed by coordination to a metal atom. Thus, Rh complexes of 1 are excellent catalysts for enantioselective hydrogenation of enamides (bottom, cod=cyclooacta-1,5-diene). Supporting information for this article is available on the WWW under http://www.angewandte.com 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.