Polyamidoamine dendrimers, constructed on the surface of silica, were phosphonated by using diphenylphosphinsmethanol, prepared in situ, and complexed to rhodium by use of [Rh(CO)(2)Cl](2). Excellent selectivities, favoring the branched aldehydes obtained from aryl olefins and vinyl esters, were observed by using the Rh(I) complex as the catalyst in hydroformylation reactions. The heterogeneous Rh (I) catalyst can also be recycled and reused without significant loss of selectivity or activity.