Rhodium-Catalyzed Regiodivergent Oxidative Annulation of Indole-2-carboxamides with Allenes via C–H Bond Activation

Reported herein is regiodivergent oxidative annulation of 2-indolylcarboxamides with benzyl allenes via C-H bond activation of the indole ring via the formation of a π-allyl intermediate. The regioselectivity is reaction-condition-dependent, selectively affording the [4 + 1]- or [4 + 3]-annulated product as a result of functionalization of the proximal or distal allylic site, respectively.