Unexpected Chemoselectivity in Radical Aryl Translocation via Photosensitization

The selective migration of aromatic rings is a fundamental tool for molecular synthesis, yet its application is constrained by the long-standing rules of chemoselectivity. Here, we report a photochemical strategy that overturns these rules. Using visible-light photosensitization, we unlock general and unexpected selectivity in radical aryl translocation. This method transforms simple carbonyl precursors into complex, three-carbon-homologated products through a sequence of energy-transfer-mediated rearrangement and strain-release ring opening. Mechanistic and computational studies reveal that the photochemical reaction inverts the conventional migratory hierarchy, favoring the translocation of challenging aryl groups over traditionally privileged heteroaryl motifs. This energy transfer enabled platform establishes a new paradigm for controlling radical reactivity and offers a powerful strategy to redirect synthetic pathways.