Chiral Phosphoric Acid Catalyzed Enantioselective Transfer Deuteration of Ketimines by Use of Benzothiazoline As a Deuterium Donor: Synthesis of Optically Active Deuterated Amines

By use of 2-deuterated benzothiazoline as a deuterium donor in combination with a chiral phosphoric acid, the transfer deuteration of ketimine and alpha-iminoester took place smoothly to give alpha-deuterated amines in high yields with excellent enantioselectivities. The remarkable kinetic isotope effect suggests that carbon-deuterium bond cleavage is the rate-determining step.