C=C Bond Oxidative Cleavage of BODIPY Photocages by Visible Light

Photocages for protection and controlled release of bioactive compounds have been widely investigated. However, the vast majority of these photocages have employed the cleavage of single bonds and high-energy ultraviolet light. The construction of a photoactivation system that uses a visible light to cleave unsaturated bonds still remains a challenge. Herein, we report a regioselective oxidative cleavage of C=C bond from a boron-dipyrrolemethene (BODIPY) based photocage by the illumination at 630 nm, resulting in a free aldehyde and a thiol fluorescent probe. This strategy was demonstrated in living HeLa cells and the generated α-formyl-BODIPY allowed the real-time monitoring aldehyde release in the cells. In particular, we showed a mannose functionalized photocage can target HepG2 cells.