Enantioselective Synthesis of Azahelicenes via Rh-Catalyzed C–H Functionalization of 6-Hydroxyisoquinoline Derivatives with Alkynes

Herein, we report an asymmetric C–H functionalization of 6-hydroxyisoquinoline derivatives and annulation with internal alkynes. The reaction is catalyzed by a chiral cyclopentadienyl (Cp)-Rh complex in combination with a modified chiral amino acid. A series of azahelicenes is afforded in good yields (up to 93%) with high enantioselectivity (up to 99% ee). A plausible catalytic cycle is proposed based on control experiments and DFT calculations, involving the reductive elimination from a high-valent Rh intermediate.