Late‐Stage Diazoester Installation via Arylthianthrenium Salts

By leveraging the fast oxidative addition of arylthianthrenium salts (aryl–TT+) to palladium(0), a regioselective diazoester installation has been developed. This approach enables the introduction of a diazo moiety to densely functionalized arenes at a late stage. The installed diazo group is amenable to facile further derivatization.