Copper-Mediated Functionalization of Aryl Trifluoroborates

This paper describes the Cu(OTf) 2 -mediated coupling of aryl and heteroaryl trifluoroborates with tetrabutylammonium or alkali metal salts to form C–O, C–N, and C–halogen bonds. The reactions proceed under mild conditions (often room temperature over 16 hours) with carboxylate, halide, and azide salts, all nucleophiles that have been underrepresented in the copper cross-coupling literature. Preliminary results show that copper salts bearing weakly coordinating X-type ligands are essential for enabling these transformations to proceed under mild conditions.