Rhodium-Catalyzed Hydrophosphorylation of Terminal Alkynes Leading to Highly Selective Formation of (E)-Alkenylphosphonates: Complete Reversal of Regioselectivity to the Palladium-Catalyzed Counterpart

Abstract

Insights into the mechanism of the rhodium-catalyzed hydrophosphorylation of alkynes with the cyclic hydrogen phosphonate 1 are provided by isolable RhIII intermediates 2 and 3. The reactions proceed at room temperature and give high yields of exclusively (E)-alkenyl phosphonates 4, which are not readily prepared by other routes. X=halide, L=phosphane or hydrogenphosphonic acid. 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.