Rh(III)-Catalyzed Chemoselective C-H Alkenylation and [5 + 1] Annulation with Gem-Difluoromethylene Enabled by the Distinctive Fluorine Effect.

The efficient couplings of diverse N-arylureas and gem-difluoromethylene alkynes have been realized via Rh(III)-catalyzed chemoselective C-H alkenylation and [5 + 1] annulation, which were induced by the distinctive fluorine effect to provide the different coordination mode of the Rh(III) catalyst binding to the directing group, thereby giving the direct access to difluorinated 2-alkenyl arylureas and 3,4-dihydroquinazolin-2(1H)-ones bearing both an α-quaternary carbon center and a monofluoroalkenyl moiety with broad substrate compatibility and good functional group tolerance. The synthetic application in C-H alkenylation of the N-pyridylaniline, the late-stage [3 + 2] annulation, and the derivation of the obtained products has been also demonstrated to further strengthen the synthetic utility of the chemodivergent transformations.