Novel Copper Complexes of Chiral Diphosphines: Preparation, Structure, and Use To Form Rhodium Complex Catalysts for Chiral Hydrogenations

Article abstract of DOI:10.1021/jo01303a016

Treatment of chiral diphosphines 5a-c and 13 ("DIOP", aryl derivatives and related substances) with CuCl in boiling ethanol gave complexes having the composition _n, 6a-c and 11.Crystallizations of 6a-c from crude 70-80percent pure 5a-c and decomposition of the complexes by ammonia gave the pure diphosphines.Ligand exchange between 6a-c and ₂ in methanol at 23 deg C was rapid and complete.Treatment of the resulting solutions with H2 gave active catalysts for asymmetric hydrogenations.