Exogenous Photocatalyst-Free Aryl Radical Generation from Diaryliodonium Salts and use in Pd-Catalyzed C–H Arylation

Diaryliodonium salts are bench stable aryl radical precursors. While photocatalysts are generally responsible for radical generation, recent reports have emerged exhibiting photocatalyst-free radical generation using select Lewis bases as activators. Herein, we demonstrate 1) the ability of numerous Lewis bases to enable light-driven radical generation and 2) these radicals can be captured by transition-metals for coupling reactions. These results are the first step toward developing new organometallic aryl radical coupling reactions without photocatalysts.