Ruthenium-Catalyzed Enantioselective C–H Functionalization: A Practical Access to Optically Active Indoline Derivatives

Ru­(II)-catalyzed enantioselective
C–H activation/hydroarylation
has been developed for the first time, allowing for highly enantioselective
synthesis of indoline derivatives via catalytic C–H activation.
Commercially available Ru­(II) arene complexes and chiral α-methylamines
were employed as highly enantioselective catalysts. Based on a sterically
rigidified chiral transient directing group, multisubstituted indolines
were produced in up to 92% yield with 96% ee. Further transformation
of the resulting 4-formylindoline enables access to an optically active
tricyclic compound that is of potential biological and pharmaceutical
interest.