[Cu(NHC)]‐Catalyzed C−H Allylation and Alkenylation of both Electron‐Deficient and Electron‐Rich (Hetero)arenes with Allyl Halides

Abstract

New reactivity of a [Cu(NHC)] (NHC=N-heterocyclic carbene) catalyst is disclosed for the efficient C-H allylation of polyfluoroarenes using allyl halides in benzene at room temperature. The same catalyst system also promotes an isomerization-induced alkenylation of initially the generated allyl arenes when the reaction is run in tetrahydrofuran. Significantly, not only electron-deficient but also electron-rich (hetero)arenes undergo this double-bond migration process, thus leading to alkenylated products. The present system features mild reaction conditions, broad scope with respect to the arene substrates and allyl halide reactants, good functional-group tolerance, and high stereoselectivity.