High‐Valent Copper Catalysis Enables Regioselective Fluoroarylation of <i>Gem</i>‐Difluorinated Cyclopropanes
Xiuli Wu, Xiangyu Song, Ying Xia
Abstract
Abstract Transition‐metal (TM) catalyzed reaction of gem ‐difluorinated cyclopropanes ( gem ‐DFCPs) has drawn much attention recently. The reaction generally occurs via the activation of the distal C─C bond in gem ‐DFCPs by a low‐valent TM through oxidative addition, eventually producing mono‐fluoro olefins as the coupling products. However, achieving regioselective activation of the proximal C─C bond in gem ‐DFCPs that overcomes the intrinsic reactivity via TM catalysis remains elusive. Here, a new reaction mode of gem ‐DFCPs enabled by high‐valent copper catalysis, which allows exclusive activation of the congested proximal C─C bond is presented. The reaction that achieves fluoroarylation of gem ‐DFCPs uses NFSI (N‐fluorobenzenesulfonimide) as electrophilic fluoro reagent and arenes as the C─H nucleophiles, enabling the synthesis of diverse CF 3 ‐containing scaffolds. It is proposed that a high‐valent copper species plays an important role in the regioselective activation of the proximal C─C bond possibly via a σ‐bond metathesis.