Nickel-Catalyzed Secondary Benzylic C-O Bond Borylation.

A remote steric hindrance ligand (-Bu)CHPCy () was synthesized to promote Ni-catalyzed C-O bond activation. The reaction achieved high yields for secondary benzylic C(sp)-O borylation in non-π-extended systems under mild conditions. Mechanistic studies indicate that the nickel complex containing 1 equiv of serves as the active catalyst, while increased loading of gives the inactive bisligated Ni species. Acetanilide is crucial for the cross-coupling reaction, which facilitates generation of the monoligated nickel species.