Modular Phosphine-Aminophosphine Ligands Based on Chiral 1,2,3,4-Tetrahydro-1-naphthylamine Backbone: A New Class of Practical Ligands for Enantioselective Hydrogenations
been achieved in the hydrogenation of most substrates tested, demonstrating the high potential of these newly developed phosphine-aminophosphineligands in asymmetric catalysis. The present research also discloses that these newly developed phosphine-aminophosphineligands are more efficient than that derived from (S)-1-phenylethylamine, suggesting that the increased rigidity conferred by a cyclohexyl
asymmetric hydrogenation of 13 different β-dehydroaminoacid derivatives to give optically active β-amino acidesters has been examined. Readily accessible monodentate octahydrobinaphthol-based phosphoramidites were used as chiral ligands. Good to excellent enantioselectivities and yields were obtained for the E isomers, whereas poorer catalyst performance was found for the Z isomers. Importantly, to obtain