Platinum Chloride–Diphosphine–Tin(II) Halide Systems as Active and Selective Hydroformylation Catalysts

The hydroformylation of 1-alkenes was efficiently catalyzed by PtCl2–diphosphine–SnX2 systems whose diphosphines were 1,4-bis(diphenylphosphino)butane derivatives with rigid ring skeletons. The effects of the structure of diphosphines, the P/Pt atomic ratio, the sort of tin(II) halide or solvent, the reaction variables, and the structure of olefins on the relative rate and the product distribution were investigated. A higher reaction rate than when using HRh(CO)(PPh3)3, and a linearity of aldehydes up to 99%, were attained. The coordination structure of the effective diphosphines as well as the reasons for the rate enhancement and for the excellent selectivity were discussed.