Monodentate Chiral Spiro Phosphoramidites: Efficient Ligands for Rhodium-Catalyzed Enantioselective Hydrogenation of Enamides

Monodentate phosphorus ligands, too, can be effective: Chiral amine derivatives can be obtained in high enantioselectivities (up to 99.7 % ee) by the asymmetric hydrogenation of enamides in the presence of rhodium complexes of the chiral spiro phosphorus ligands (S)-1, the first monodentate P ligands that are effective in this class of reactions.