Bisannulation of Benzamides and Cyclohexadienone-Tethered Allenes Triggered by Cp*Rh(III)-Catalyzed C-H Activation and Relay Ene Reaction.

The diastereoselective bisannulation of N-(pivaloyloxy)benzamides and cyclohexadienone-tethered allenes was accomplished through Cp*Rh(III)-catalyzed C-H activation and relay ene reaction, providing a 3-isoquinolonyl cis-hydrobenzofuran framework with high yields and diastereoselectivities. This reaction tolerates a wide range of functional groups, enabling further conversions to tricyclic and bridged-ring structures. Moreover, the dearomatization modification of phenol-contained bioactive molecule is also elaborated.