Chemoselective Transfer Hydrogenation of Enamides Using Ru Pincer Complexes for the Synthesis of α-Amino Acids.

The chemoselective reduction of enamides to α-amino acids with i PrOH and EtOH as H-donors and solvents catalyzed by Ru pincer complexes is demonstrated. A range of α-amino acids is synthesized in good to excellent yields. Applications, large scale, and a one-pot experiment are also reported. Finally, deuterium-labeling experiments show high regioselectivity between the α- and β-positions of the alkene unit.