Rhodium(III)-Catalyzed Annulative Carbooxygenation of 1,1-Disubstituted Alkenes Triggered by C-H Activation.

A Cp*RhIII -catalyzed annulative carbooxygenation of challenging 1,1-disubstituted alkenes triggered by C-H activation of N-aryloxyacetamides has been established, which affords 2,3-dihydrobenzofuran derivatives with a quaternary carbon center in good to excellent yields under mild redox-neutral conditions. An amide group on the alkenes is essential for the process, and may inhibit the β-H elimination from C(sp3)-Rh species by saturating the rhodium center through coordination. Furthermore, mechanistic insights obtained from control experiments suggest a mechanism involving a RhIII -RhV -RhIII catalytic cycle.