Metal‐Catalyzed Direct C–H Fluoroalkenylation of Pyridine N‐Oxides and Related Derivatives

The copper‐ and palladium/copper‐catalyzed direct C–H fluoroalkenylation of pyridine N‐oxides and related heterocycles using various gem‐bromofluoroalkenes as electrophiles is reported. The dimetallic palladium/copper process proved to be more efficient than copper catalysis, giving access to various relevant 2‐fluoroalkenylated azines. Two catalytic systems have been studied for the coupling of gem‐bromofluoroolefins with pyridine N‐oxides and related heterocycles for the first time. Copper catalysis offers a low‐cost access to fluoroalkenes in fair yields but dimetallic catalysis proved to be more efficient, allowing the direct C–H fluoroalkenylation of the pyridine N‐oxides and their derivatives in medium to quantitative yields.