Rapid Methylation of Aryl Bromides Using Air‐Stable DABCO‐Bis(Trimethylaluminum) via Nickel Metallaphotoredox Catalysis

We report a metallaphotocatalytic strategy for the selective methylation of (hetero)aryl bromides via nickel‐catalyzed cross‐coupling with bis(trimethylaluminum)‐1,4‐diazabicyclo[2.2.2]octane (DABAl‐Me₃), as a commercially available, air‐stable, and non‐pyrophoric aluminum‐based reagent. The method enables a fast, robust, and scalable methylation protocol that broadly accommodates various functional groups while preventing protodehalogenation. Mechanistic studies confirm the unprecedented generation of methyl radicals from an organo‐aluminum precursor under photoredox conditions, bypassing the limitations of conventional two‐electron pathways. This work expands the toolbox of practical radical precursors and provides a streamlined approach for selective C(sp 2 )─CH 3 bond formation.