Researchers at the University of Osaka have made significant strides in chemical synthesis by using visible light to activate aryl iodides in a rare bond-breaking reaction. This breakthrough was reported on July 2, 2026, in the Journal of the American Chemical Society.
Innovative Approach to Oxidative Addition
The oxidative addition of aryl iodides at a gallium(I) center marks a pivotal advancement in the field. Traditionally, transition metals like palladium and nickel have been utilized for this purpose, but they are costly and scarce. The research team, led by Nijito Mukai, has successfully demonstrated that gallium, a more abundant group 13 element, can be used instead.
“The only known case of oxidative addition with a group 13 center is for aryl fluoride,” explains Mukai. “However, we were able to perform the reaction with an aryl iodide, an important species in chemical synthesis.” This novel use of gallium could potentially transform how chemical reactions are facilitated in laboratories.
Mechanism Behind the Reaction
The study reveals that the reaction proceeds through a mechanism known as photoinduced disproportionation. In this process, an element in the reactant is altered into both higher and lower oxidation states, enabling further organic reactions. Senior author Takuya Kodama notes, “In our strategy, photoexcited gallium exchanges electrons with ground-state gallium to produce a radical ion pair.”
