Nickel-Catalyzed NO Group Transfer Coupled with NO x Conversion

Nitrogen oxide (NO x ) conversion is an important process for balancing the global nitrogen cycle. Distinct from the biological NO x transformation, we have devised a synthetic approach to this issue by utilizing a bifunctional metal catalyst for producing value-added products from NO x . Here, we present a novel catalysis based on a Ni pincer system, effectively converting Ni–NO x to Ni–NO via deoxygenation with CO­(g). This is followed by transfer of the in situ generated nitroso group to organic substrates, which favorably occurs at the flattened Ni­(I)–NO site via its nucleophilic reaction. Successful catalytic production of oximes from benzyl halides using NaNO2 is presented with a turnover number of >200 under mild conditions. In a key step of the catalysis, a nickel­(I)–•NO species effectively activates alkyl halides, which is carefully evaluated by both experimental and theoretical methods. Our nickel catalyst effectively fulfills a dual purpose, namely, deoxygenating NO x anions and catalyzing C–N coupling.