Thermal CO Release Reactivity of a π‑Extended Flavonol Anion

The π-extended flavonol Flav-1 (1) undergoes reaction with KOH or KO2 to form 1 – , which reacts with O2 at ambient temperature, resulting in CO release and depside formation. Mechanistic and DFT studies support a reaction pathway involving reaction of 1 – with O2 on the triplet energy surface in the rate-determining step. Formation of a cyclic peroxide leads to CO extrusion. These studies indicate that if formed in biological environments, 1 – will release CO in the absence of light illumination.