Iron-Catalyzed Triazole-Enabled C–H Activation with Bicyclopropylidenes

C–H/C–C
functionalizations with oxymethylated bicyclopropylidenes
were accomplished with an iron catalyst under external oxidant-free
conditions. The combination of the unique reactivity of bicyclopropylidenes
with a robust iron­(II) catalyst enabled C–C cleavages in a
chemoselective fashion, which allows for the synthesis of isoquinolones,
free isoquinolones, or bispiro-fused isoquinolones. Mechanistic studies
provided strong support for the C–C cleavage via β-C elimination. A rare monoselective C–F/C–H bond functionalization
of trifluoromethylarene was also observed.