Light Up the Transition Metal-Catalyzed Single-Electron Allylation

Transition metal-catalyzed allylations are among the most important tools for the formation of chemical bonds. Unlike soft nucleophiles (pK(a) < 25), reactions of hard nucleophiles (pK(a) > 25) usually suffer from requiring organometallic reagents or the use of strong bases. In addition, traditional single-electron allylations always require rigorously controlled reaction conditions as well as the use of a stoichiometric reductant that often reduces functional group tolerance. Single-electron allylation reactions facilitated by synergistic transition-metal catalysis and visible light photocatalysis, however, can provide complementary advantages over traditional allylations. From this perspective, we highlight the recently discovered single-electron allylation reactions exploiting this synergistic catalysis strategy.