Ruthenium-Catalyzed Enantioselective Hydrogenation of Phenanthridine Derivatives

The first asymmetric
hydrogenation of phenanthridines catalyzed
by chiral cationic ruthenium diamine complexes has been developed
with up to 92% ee and full conversions. The choice of the counteranion
of the catalyst was found to be critical for achieving high enantioselectivity.
In addition, the obtained 5,6-dihydrophenanthridine could be used
as a chiral hydride donor for organocatalytic asymmetric transfer
hydrogenation.