ASYMMETRIC EPOXIDATION OF SIMPLE OLEFINS CATALYZED BY CHIRAL DIPHOSPHINE-MODIFIED PLATINUM(II) COMPLEXES

The synthesis of a class of chiral diphosphine-modified platinum(II) complexes of the type P2*Pt(CF3)X (P2 = chiraphos, prophos, diop; X = Cl, OH) is reported. These have been characterized with IR and19F and31P{111XH) NMR spectroscopy. The hydroxo complexes and the corresponding [P2*Pt(CF3)-(CH2C12)](BF4) cationic solvato complexes have been used as catalysts in the epoxidation of 1-octene and propene with diluted hydrogen peroxide. The obtained epoxides are optically active with enantiomeric excess (ee) as high as 41%. The capacity of the catalysts to induce asymmetry is discussed on the basis of the stereochemical rigidity of the metal-diphosphine array that has been investigated with variable-temperature19F NMR experiments. © 1987, American Chemical Society. All rights reserved