Unsymmetrical ferrocenylethylamine-derived monophosphoramidites: Highly efficient chiral ligands for Rh-catalyzed enantioselective hydrogenation of enamides and alpha-dehydroamino acid derivatives

A new family of unsymmetrical ferrocenylethylamine derived monophosphoramidites were synthesized and successfully applied in the Rh-catalyzed enantioselective hydrogenation of a range of enamides and alpha-dehydroamino acid esters, and ee values of upto 9.5% were obtained for both types of substrate. These results suggest that unsymmetrical amine-derived monophosphoramidites also exhibit excellent enantioselectivity for a broad range of substrates.