Asymmetric Transfer Hydrogenation of Imines using Alcohol: Efficiency and Selectivity are Influenced by the Hydrogen Donor.

The influence of the alcohol, as the hydrogen donor, on the efficiency and selectivity of the asymmetric transfer hydrogenation (ATH) of imines is reported for the first time. This discovery not only leads to a highly enantioselective access to N-aryl and N-alkyl amines, but also provides new insight into the mechanism of the ATH of imines. Both experimental and computational studies provide support for the reaction pathway involving an iridium alkoxide as the reducing species.