Epoxidation of Olefins Catalyzed By Chelating Diphosphine Platinum(II) Complexes - Ring-size and Ring-shape Effects On the Catalytic Activity

The epoxidation of 1-octene with H2O2 has been examined by using as catalysts a homologous class of 10 (diphosphine)Pt-(CF3)(solv)+ and 10 (diphosphine)Pt(CF3)(OH) type complexes, where the diphosphine has been systematically varied. All diphosphines contain two -PPh2 groups but differ in the hydrocarbon chain linking together the two phosphorus atoms. The epoxidation reaction experimental conditions have been chosen in order to study the effect of the metal-diphosphine ring size and ring shape on the catalytic activity. It appears that diphosphine complexes with rigid, five-membered chelate rings prove to be the best catalysts.