Hydroformylation of alkenes with paraformaldehyde catalyzed by rhodium–phosphine complexes

The hydroformylation of medium-chain C6 olefins and of allyl alcohol was achieved with paraformaldehyde in dioxane solution using rhodium catalysts with mono-, bi-, and tri-dentate phosphine ligands. The highest activities with n/i ratios around 2, were obtained for a system derived from [Rh(dppe)2]+, prepared in situ by reaction of Rh(acac)(CO)2 with 2 eq of dppe.