Rhenium(I)-Catalyzed ortho-C-H Addition to Bicyclic Alkenes

Hydroarylation of bicyclic alkenes has been developed using a low-valent Re-I-catalyzed, directing group-assisted C-H bond activation strategy. The addition of sodium acetate significantly improves the reaction efficiency; moreover, bicyclic alkenes such as 7-oxa and aza benzonorbornadienes worked efficiently under this reaction condition. Preliminary mechanistic studies suggest that, after the alkene insertion, the rhenacycle preferentially undergoes protonolysis rather than reductive elimination.