Catalytic activity enhancement of a cyclodextrin/water-soluble-rhodium complex system due to its gradual supramolecular organization in the interphase

Heavy terminal alkenes can be hydroformylated at a significant rate by usin g the water-soluble catalyst precursor [Rh-2(mu -StBu)(2)(CO)(2)(TPPTS)(2)] and beta -cyclodextrin or its dimethylated form as phase-transfer agent. A study of the recycling has shown that the aqueous phase can be directly re introduced into catalysis and also that each new run presents a slightly hi gher level of activity. Careful examination of the parameters of this catal ysis leads us to propose that a gradual supramolecular organization in the interphase occurs for the rhodium complex, its solvation sphere and cyclode xtrin which should involve at least two molecules in a head-to-tail or head -to-head arrangement.