Diastereoselective Hydrodifluoromethylation of Alkenyl <i>N</i>-Heterocycles via Photocatalytic Radical-Polar Crossover

A diastereoselective hydrodifluoromethylation of <i>N</i>-heteroaryl alkenes was successfully established. This method was applicable to an array of <i>N</i>-heteroaryl substrates with both cyclic and acyclic alkenes while displaying tolerance to a variety of functional groups. The conditions were also expanded to obtain hydrotrifluoromethylated products with similar results. Initial mechanistic studies suggest that the final protonation step is accessed through a radical-polar crossover process.