A Singlet Oxygen‐Mediated Route to <i>O</i> , <i>O</i> ‐Bidentate BF ₂ Complexes via Visible‐Light‐Driven Ring Opening of Isoxazoles

ABSTRACT A strategy for the O , O ‐bidentate BF 2 complexation from isoxazole via N─O bond cleavage, N → O replacement, followed by BF 2 insertion, accompanied by ring closing, is accomplished. This non‐hydrolytic path proceeds through a sequence involving isoxazole ring opening via N─O bond cleavage, generating an azirine intermediate, which then reacts with the in situ generated singlet oxygen ( 1 O 2 ). Subsequent elimination of nitric oxide (NO) and BF 2 insertion affords a highly luminogenic borylated product.