New heterogenized C2-symmetric bis(sulfonamide)-cyclohexane-1,2-diamine-RhIIICp∗ complexes and their application in the asymmetric transfer hydrogenation (ATH) of ketones in water

C2-symmetric bis(sulfonamide) ligands derived from chiral trans-(1R,2R)-cyclohexane-1,2-diamine were immobilized on silica gel and on polystyrene resin, and complexed to RhIIICp∗. The resulting complexes were used as catalysts in the asymmetric transfer hydrogenation (ATH) of acetophenone. The chiral secondary alcohol was obtained in high yields (>99%) and enantioselectivities (92%) with aqueous sodium formate as the hydride source. The immobilized catalysts were recycled with no loss in activity.