Photosensitizer-Free, Gold-Catalyzed C-C Cross-Coupling of Boronic Acids and Diazonium Salts Enabled by Visible Light

The first photosensitizer-free visible light-driven, gold-catalyzed C-C cross-couplings of arylboronic acids and aryldiazonium salts are reported. The reactions can be conducted under very mild conditions, using a catalytic amount of tris(4-trifluoromethyl)phosphinegold(I) chloride [(4-CF3-C6H4)(3)PAuCl] with methanol as the solvent allowing an alternative access to a variety of substituted biaryls in moderate to excellent yields with broad functional group tolerance.