| abstract |
The solution relates to a method of preparing sitagliptin of formula I, comprising hydrogenation of an enamino-amide precursor of formula II, wherein the hydrogenation is carried out in a suspension or a solution and is catalyzed by a complex compound formed of Ru and an (R) or (S)-pseudo-o-bisphosphino-[2,2]-paracyclophane ligand of general formula VI, wherein R are the same or different substituents from the group consisting of C 1-4 alkyls, C 3-8 cycloalkyls and Ar, and Ar is an unsubstituted or substituted aryl, and optionally other component(s) necessary for formation of the complex compound. |