Iridium-catalyzed enantioselective hydrogenation of imines with xylose diphosphite and diphosphinite ligands

Iridium complexes incorporating xylose diphosphinite 1 and diphosphite 2, 3 ligands as source of chirality are active catalysts for the hydrogenation of imines providing moderate ee. The enantioselectivity depends on the fine tuning of the structural parameters of the ligand and on the effect of additives.