Technical Notes:
1. L igand used for the Rh-catalyzed asymmetric hydrogenation of a-substituted acrylic acids .
2.Ligand used for the Rh-catalyzed asymmetric hydrogenation of 3-aryl-2- ethoxy-acrylic acids.
Reference:
1. Angew. Chem. Int. Ed. 2007, 46, 4141.