Sulfonamido-phosphoramidite ligands in cooperative dinuclear hydrogenation catalysis

Sulfonamido−phosphoramidite ligands lead to the formation of Rh−Rh dinuclear complexes through the anionic P−N− bridging character. The resulting "boat-shaped" dinuclear catalysts activate molecular H2 through a cooperative dinuclear endocyclic mechanism, resulting in one bridging and one classical hydride on the dinuclear complex. These new complexes are very active hydrogenation catalysts that operate via a new cooperative hydrogenation activation mechanism, as calculated with density functional theory, and they display unequaled high selectivities in the hydrogenation of hindered cyclic acetamidoalkenes.