Ruthenium catalyst and its use in asymmetric hydrogenation of weakly coordinating substrates

摘要

A catalyst of ruthenium (II) comprising bidentate phosphine ligands is described which is obtained by a process that comprises treating equimolar amounts of an appropriate Ru(II) complex and a bidentate diphosphine ligand with an acid of the formula HX, wherein X is a non-coordinating anion, said acid being used in a ratio of 1 molar equivalent per mole of Ru(II) complex and the treatment being carried out in a non-coordinating or weakly coordinating medium, under an oxygen-free atmosphere. Said catalyst is useful for the preparation of the preferred isomer of the Hedione3, having the configuration (+)-(1R)-cis, and of many other substrates comprising highly hindered carbon-carbon double bonds.