Gallium has been caught performing a chemical trick that was previously thought to be impossible for anything but heavy transition metals.
April 23, 2026
Original Paper
Photoinduced Disproportionation Enables Oxidative Addition of Aryl Iodides at a Gallium(I) Center
ChemRxiv · chemrxiv.15002270/v1
The Takeaway
This main group element can now break and reform carbon iodine bonds using a light induced radical mechanism. This process, called oxidative addition, is the cornerstone of modern industrial chemistry and was long considered the exclusive domain of metals like platinum or gold. Using gallium is much cheaper and more sustainable than relying on those rare and expensive catalysts. It opens up an entirely new way to build complex molecules for medicine and plastics.
From the abstract
Oxidative addition at transition metals underpins modern cross-coupling catalysis but remain largely unrealized at main-group centers for aryl halides. Here, we show that photoinduced disproportionation can serve as an enabling strategy for such transformations. Visible light promotes oxidative addition of aryl iodides to a Ga(I) metallylene, providing, to our knowledge, the first example of aryl C(sp²)–I activation at a monovalent group 13 center. Mechanistic studies suggest that this transform