Supported rhodium and iridium 2,2′-bipyridine complexes were prepared for the hydrogenation of aromatic ketones under hydrogen pressure. The key feature of the immobilization process is the functionalization of the 2,2′-bipyridine unit with two phosphonic acid moieties, thus allowing the covalent grafting of the catalytic complex onto in situ generated titanium oxide particles. A very good catalytic activity is observed with the resulting materials that compares well with the homogeneous parent system and gives evidence that the major part of the catalytic sites are readily accessible. Moreover, the catalyst can be reused, and no significant rhodium leaching is observed.

New water‐soluble rhodium and iridium complexes of 2,2′‐bipyridines, functionalized with PO3Na2 groups, show very good catalytic activities in the reduction of various substituted acetophenones under hydrogen pressure in basic aqueous media. No significant loss of catalyst activity is observed after one use.