Optically active chiral diphosphine ligands

This invention relates to the use of chiral diphosphines as optically active ligands for the preparation of diphosphino-metal complexes. The invention also pertains to the diphosphino-metal complexes comprising a chiral diphosphine as ligand and the asymmetric catalysis processes employing these complexes. The invention envisages more particularly the use of these diphosphino-metal complexes in asymmetric hydrogenation or isomerization processes for the synthesis of organic products of specified chirality. An (R) or (S) chiral diphosphine of formula (I): wherein R and R1, which can be identical or different, represent an optionally saturated Calkyl group, an optionally saturated Ccycloalkyl group, a Caryl group, the groups being optionally substituted by a halogen, a hydroxy, a Calkoxy, an amino, a sulfino, a sulonfyl, with Rrepresenting an alkyl, an alkoxy or an alkylcarbonyl, the alkyl, cycloalkyl, aryl groups optionally including one or more heteroatoms, or R and R1 together represent an optionally saturated Csubstituted alkyl group, an optionally saturated Ccycloalkyl group, a Caryl group, the cycloalkyl or aryl groups being optionally substituted by a Calkyl, a halogen, a hydroxy, a Calkoxy, an amino, a sulfino, a sulonfyl, with Rrepresenting an alkyl, an alkoxy or an alkylcarbonyl, the alkyl, cycloalkyl, aryl groups optionally including one or more heteroatoms, R2 and R3, which can be identical or different, represent an optionally saturated Ccycloalkyl group, a Caryl group, the groups being optionally substituted by a halogen, a hydroxy, a Calkoxy, an amino, a sulfino, a sulonfyl, with Rrepresenting an alkyl, an alkoxy or an alkylcarbonyl, the cycloalkyl, aryl groups optionally including one or more heteroatoms, or R2 and R3 together form an optionally saturated Ccyclic group, a Caryl group, the groups being optionally substituted by a halogen, a hydroxy, a Calkoxy, an amino, a sulfino, a sulonfyl, with Rrepresenting an alkyl, an alkoxy or an alkylcarbonyl, the cyclic and aryl groups optionally including one or more heteroatoms.