Asymmetric Synthesis of Functionalized gem -Difluoromethylenecyclopropanes via Rh(III)-Catalyzed Redox-Neutral C–H Coupling

Fluorinated cyclopropane skeletons possess significant synthetic utility and medicinal potential. Herein, the Rh(III)-catalyzed redox-neutral C-H coupling of indole derivatives with gem-difluorocyclopropenol carboxylates was realized in both a racemic and asymmetric manner, giving access to the divergent synthesis of functionalized gem-difluoromethylenecyclopropanes with broad substrate compatibility, good enantioselectivity, and profound synthetic application. This protocol occurred via a tandem C-H activation/alkene insertion/β-O elimination process, thereby precluding the competitive fluoride elimination and ring scission of the strained cyclopropane.