Deoxygenative ortho-benzylation of aryl iodides with benzyl alcohol via palladium/norbornene cooperative catalysis

Herein, we demonstrate a robust palladium/norbornene-catalyzed deoxygenative ortho-benzylation of aryl iodides with non-derivatized benzyl alcohol, which enables the assembly of various diarylmethanes with high efficiency. Assisted by a carbodiimide, the alcohol is transiently converted into the corresponding isourea, which further polarizes the C-O bond and facilitates the reaction with the key aryl-NBE-palladacycle (ANP) intermediate through nitrogen atom coordination. The salient features of this methodology include operational simplicity, high chemoselectivity, and broad substrate scope. A preliminary mechanistic investigation indicated the higher reactivity of the isourea compared to the corresponding benzyl (pseudo)halide.