Controlled Copper‐Catalyzed Oxygenation of α‐Methyl BODIPYs: Access to Hydroxymethylated and Formylated Dyes

α‐Hydroxymethylated and α‐formylated BODIPYs are valuable fluorescent dyes and synthetic intermediates, yet their direct and controllable preparation from common α‐methyl‐substituted precursors remains challenging. Herein, we report a controlled copper‐catalyzed oxygenation of methyl BODIPYs that enables oxidation‐level‐divergent synthesis of hydroxymethylated and formylated dyes. Using a CuI/2,2′‐bipyridine/Na 2 CO 3 system in DMSO, α‐methyl BODIPYs were selectively converted into mono‐hydroxymethylated derivatives under mild conditions. By modifying the reaction parameters and substrate structures, the oxidation level could be further advanced to provide dihydroxymethylated and diformylated BODIPYs in a tunable manner. Preliminary control experiments are consistent with a copper‐mediated oxygenation pathway involving α‐methyl C─H activation and divergent transformation of peroxide‐type intermediates. The hydroxymethylated products largely retain the characteristic absorption and fluorescence features of the parent dyes, whereas formylated derivatives show more pronounced electronic modulation, including bathochromically shifted absorption and emission. This work provides a concise and oxidation‐level‐tunable late‐stage oxygenation strategy for expanding the chemical space of BODIPY dyes.