Nickel-Catalyzed\nSecondary Benzylic C–O Bond\nBorylation

A remote steric hindrance ligand (<i>m</i>-<sup><i>t</i></sup>Bu)<sub>2</sub>C<sub>6</sub>H<sub>3</sub>PCy<sub>2</sub> (<b>L1</b>) was synthesized to promote Ni-catalyzed\nC–O bond activation. The reaction achieved high yields for\nsecondary benzylic C(sp<sup>3</sup>)–O borylation in non-π-extended\nsystems under mild conditions. Mechanistic studies indicate that the\nnickel complex containing 1 equiv of <b>L1</b> serves as the\nactive catalyst, while increased loading of <b>L1</b> gives\nthe inactive bisligated Ni species. Acetanilide is crucial for the\ncross-coupling reaction, which facilitates generation of the monoligated\nnickel species.