Rhodium-catalysed C(sp2)–C(sp2) bond formation via C–H/C–F activation

Fluoroalkenes represent a class of privileged structural motifs, which found widespread use in medicinal chemistry. However, the synthetic access to fluoroalkenes was much underdeveloped with previous reported methods suffering from either low step economy or harsh reaction conditions. Here we present a Rh III -catalysed tandem C–H/C–F activation for the synthesis of (hetero)arylated monofluoroalkenes. The use of readily available gem -difluoroalkenes as electrophiles provides a highly efficient and operationally simple method for the introduction of α-fluoroalkenyl motifs onto (hetero)arenes under oxidant-free conditions. Furthermore, the employment of alcoholic solvent and the in-situ generated hydrogen fluoride are found to be beneficial in this transformation, indicating the possibility of the involvement of hydrogen bond activation mode with regards to the C–F bond cleavage step. Fluoroalkenes are found widely in biologically active compounds, but their introduction can be difficult or laborious. Here, the authors report a C–H/C–F activation strategy to introduce monofluoroalkenes into organic molecules in one step with good to excellent yields.