New unsymmetrical hybrid ferrocenylphosphine-phosphoramidite ligands derived from H8-BINOL for highly efficient Rh-catalyzed enantioselective hydrogenation

A series of new H-8-BINOL-derived unsymmetrical hybrid ferrocenylphosphine-phosphoramidite ligands have been synthesized and successfully used in Rh-catalyzed asymmetric hydrogenations. The same or higher enantioselectivities (99.9% ee) were achieved in the hydrogenation of dimethyl itaconate and alpha-dehydroamino acid esters as those obtained with BINOL-derived analogues. However, slightly lower enantioselectivities (99.0% ee) were obtained in the hydrogenation of enamides. (C) 2005 Elsevier Ltd. All rights reserved.