Highly Efficient Rh(I)-Catalyzed Asymmetric Hydrogenation of Enamines Using Monodente Spiro Phosphonite Ligands.

The article discusses the development of highly enantioselective hydrogenation of simple N-unprotected enamines catalyzed by a Rh(I) complex of chiral spiro phosphonite ligand (S)-1c, which provided a straightforward method for the synthesis of chiral tertiary amines with great ee values. Chiral amines are an important class of compounds in organic and pharmaceutical synthesis. The catalytic asymmetric hydrogenation of N,N-diakylenamines is one of the most straightforward accesses to the optically active tertiary 1,2-diarylethanamines.