Catalytic process

A catalytic process for the hydroformylation of olefins having from 3 to 20 carbon atoms to produce a high n:iso ratio of aldehyde product comprising reacting together at elevated temperature and pressure the olefin, hydrogen and carbon monoxide in the presence of a catalyst comprising a water-soluble complex of a platinum group metal in a reaction medium comprising an aqueous phase and an organic phase and in the further presence of an amphiphilic reagent, the aqueous phase containing the catalyst, the organic phase containing the olefin, the amphiphilic reagent permitting the olefin to cross from the organic phase into the aqueous phase and enabling the resulting product aldehyde to cross into the organic phase, said amphiphilic reagent being substantially soluble in the aqueous phase and substantially insoluble in the organic phase, the reaction temperature being in the range 40.degree.-150.degree. C. and the reaction pressure being in the range 300-10000 kPa, the ratio of aqueous phase to organic phase being in the range of 0.33:1 to 5:1 and the concentration of amphiphilic reagent to precious metal being up to 100:1 on a molar basis.