Aryldiazonium salts can serve as nitrogen-based Lewis acid catalysts and their applications in the formation of photoactive charge transfer complexes

We report the Lewis acid catalysis of aryldiazonium salts, and their Lewis acidity applications in photogeneration of aryl radicals under additive-, photocatalyst- and transition metal-free conditions. In this visible light-mediated transformation, the Lewis acidic character of aryldiazonium salts enables access to the photoactive charge transfer complex with dichalcogenides. The usefulness and versatility of this new protocol are demonstrated through the chalcogenation of a variety of aryldiazonium salts.