Asymmetric transfer hydrogenation reaction in water: Comparison of chiral proline amide/amine ruthenium(II) complexes

Chiral proline amide/amine ligands (2, 3), synthesized by multi-step reaction starting from L-proline (1), were evaluated as catalyst generated in situ from [RuCl2(p-cymene)](2) for asymmetric transfer hydrogenation of aromatic ketones in the presence of sodium formiate and sodium dodecyl sulfate (SDS). The results revealed that efficiencies and enantioselectivities strongly depend on the N-substituents. (C) 2014 Elsevier B.V. All rights reserved.