Facile heterogeneous catalytic hydrogenations of C=N and C=O bonds in neat water: anchoring of water-soluble metal complexes onto ion-exchange resins

Rare examples are known of non-covalent immobilization of water-soluble transition metal complexes onto solid supports and their application in catalytic hydrogenations in neat water. In the present work we report on the synthesis of a novel Ir(I) complex bearing the water soluble monodentate cage phosphine PTA (PTA = 1,3,5-triaza-7-phosphaadamantane) and its immobilisation onto commercial ion-exchange resins by a straightforward heterogenization method. The materials obtained were used as catalysts for the hydrogenations of cyclic imines and ?-keto esters under mild conditions using water as a green reaction medium, avoiding as much as possible the use of toxic and/or hazardous solvents.