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

Hydroarylation of bicyclic alkenes has been developed using a low‐valent ReI‐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. ReI‐catalyzed ortho C−H activation of aryl pyridines with oxa/aza‐bicyclic alkenes provides access to ortho‐alkylation products with excellent exo‐selectivity.