Pd(0)-Catalyzed Intermolecular Methylene C(sp 3 )-H Silylation by Using N -Heterocyclic Carbene Ligands.

The direct functionalization of methylene C(sp 3 )-H bonds is one of the greatest challenges in transition metal-catalyzed C-H activation. Although Pd(0)-catalyzed intramolecular cyclization reactions of methylene C(sp 3 )-H bonds have been reported, intermolecular functionalization remains to be discovered. Herein, we report the first example of a Pd(0)-catalyzed intermolecular methylene C(sp 3 )-H functionalization reaction. By use of a N -heterocyclic carbene ligand, the methylene C(sp 3 )-H bonds of 1-(benzyloxy)-2-iodobenzenes are activated and disilylated with hexamethyldisilane, affording disilylated products.