Tandem C(sp2)–OMe Activation/C(sp2)–C(sp2) Coupling in Early Transition-Metal Complexes: Aromatic C–O Activation beyond Late Transition Metals

We report on combined structural, kinetic, and computational studies unraveling the mechanism of a unique, highly selective intramolecular C­(sp2)–OMe cleavage/C­(sp2)–C­(sp2) coupling tandem reaction in group 3 metal (Y and Sc) complexes of amidine-amidopyridinate ligands. The latter process represents a rare stoichiometric model of the nonredox cleavage of inert C­(sp2)–O bonds relevant to cross-coupling reactions of aromatic ethers catalyzed by late transition metals.