Cobalt-catalyzed hydrogenation of β-enamino esters using an internal mixture of bidentate and monodentate ligands

Different β-amino esters have been obtained in good yields by means of octacarbonyldicobalt-catalyzed hydrogenation of β-enamine esters in the presence of mixture of a bidentate phosphine chiral (R-BINAP) and a monodentate phosphine achiral (PPh3). Likewise, a non-symmetric Co/BINAP/PPh3 complex was isolated. This new compound was used in the hydrogenation reaction under different conditions and the results suggest that this heterocombination could be responsible for improving enantiomeric excess in the reduction products.