Stereoselective β–F Elimination Enabled Redox-Neutral [4 + 1] Annulation via Rh(III)-Catalyzed C–H Activation: Access to <i>Z</i>-Monofluoroalkenyl Dihydrobenzo[<i>d</i>]isoxazole Framework

Abstract

An efficient and practical Rh(III)-catalyzed redox-neutral [4 + 1] annulation of N-phenoxy amides with α, α-difluoromethylene alkynes has been realized to give direct access to the Z-configured monofluoroalkenyl dihydrobenzo[ d]isoxazole framework with broad substrate compatibility and good functional group tolerance, which was further enhanced by the late-stage C-H modification of complex bioactive compounds. Subsequent density functional theory calculations revealed that the stereoselective β-F elimination involving an allene species played a decisive role in determining the reaction outcome and such Z-selectivity.