Hypervalent Iodine(III)-Promoted C3–H Regioselective Halogenation of 4‑Quinolones under Mild Conditions

A simple and practical
protocol for the C3–H regioselective
halogenation of 4-quinolones by the action of potassium halide salt
and PIFA/PIDA in good to excellent yields was developed. The current
approach provides feasible access to the diversity of C3-halgenated
4-quinolones at room temperature with high regioselectivity and good
functional group tolerance, from which bioactive compounds can be
easily constructed. Moreover, the current method featured eco-friendly,
operational convenience and is suitable for halogenation in a gram
scale of 4-quinolones in water without sacrificing yields.