Gallium uses visible light to activate aryl iodides in rare bond-breaking reaction

Cross-coupling reactions have revolutionized the synthesis of complex pharmaceuticals and polymers from simpler, commercially available products. An important first step in these reactions is oxidative addition, which is often facilitated using transition metals such as palladium and nickel. However, achieving the same transformation with more abundant main-group elements, found in groups 1–2 and 13–18 of the periodic table, remains a major challenge for many important substrates, particularly aryl halides.