Ni/Photoredox-Catalyzed C(sp2)-C(sp3) Cross-Coupling of Alkyl Pinacolboronates and (Hetero)Aryl Bromides

Utilizing quinoline as a mild, catalytic additive, broadly applicable conditions for the Ni/photoredox-catalyzed C(sp(2))-C(sp(3)) cross-coupling of (hetero)aryl bromides and alkyl pinacolboronate esters were developed, which can be applied to both batch and flow reactions. In addition to primary benzylic nudeophiles, both stabilized and nonstabilized secondary alkyl boronic esters are effective coupling partners. Density functional theory calculations suggest that alkyl radical generation occurs from an alkyl-B(pin)-quinoline complex, which may proceed via an energy transfer process.

Automated summary

By utilizing quinoline as a mild catalytic additive, a broadly applicable method for Ni/photoredox-catalyzed C(sp(2))-C(sp(3)) cross-coupling was developed, which can be used in both batch and flow reactions. The method is effective for both primary benzylic nucleophiles and stabilized/nonstabilized secondary alkyl boronic esters.