Process for hydrogenating unactivated imines using ruthenium complexes as catalysts

A process for preparing enantiomerically enriched chiral dialkyl, alkylalkenyl or dialkenyl amines of formula III, or the opposite enantiomer thereof, from an imine of formula II:

• wherein
• R1 and R2 are independently selected from the group consisting of optionally substituted cyclic, linear and branched alkyl and alkenyl and wherein R1 and R2 may also be linked together, or with R3, to form one or more rings;
• and
• R3 is selected from the group consisting of hydrogen, hydroxy, optionally substituted C1 to C8 cyclic, linear and branched alkyl and alkenyl, and optionally substituted aryl;
• said process comprising reacting imines of formula II in the presence of H2 and a catalytic system comprising a base and a ruthenium complex containing (1) a diamine and (2) a chiral diphosphine ligand or chiral monodentate phosphine ligands.