Industrially relevant product selectivities and reaction rates are obtained from rhodium catalyzed hydroformylation of propylene via the use of a novel induction period in which the supramolecular ligand assembly, the rhodium precatalyst and an initial substrate are allowed to form a hydroformylation catalyst that is more selective toward branched aldehydes. Upon heating this incubated mixture and addition of propylene, iso-butyraldehyde is obtained in higher concentrations and rates that are otherwise unattainable.