Highly Enantioselective [2+2+2] Cycloaddition of Enediynes Enabled by Cobalt/Organophotoredox Cooperative Catalysis

Herein,
we report dual cobalt and photoredox catalysis enabled
[2+2+2] cycloaddition of enediynes to produce tricyclic cyclohexadienes
bearing a quaternary bridgehead carbon. A variety of enediynes were
used, and the corresponding cyclohexadienes were obtained in good
to high yields. The use of a chiral ligand, (S)-Segphos,
enabled a highly enantioselective reaction allowing access to highly
enantio-enriched cyclohexadienes.