Achiral Ligands Dramatically Enhance Rate and Enantioselectivity in the Rh/Phosphoramidite-Catalyzed Hydrogenation of alpha,beta-Disubstituted Unsaturated Acids

摘要

In 2000,three research groups demonstrated that the widely held view that chiral bidentate ligands are necessary to achieve high enantioselectivity in rhodium-catalyzed hydro-genations needs revision.Monodentate phosphonites,[lal phosphites[lbI and phosphoramidites[lcl proved to be highly versatile ligands for this important transformation and afforded excellent enantioselectivities for a broad range of substrates.