Solvent Effects: Syntheses of 3,3-Difluorooxindoles and 3‑Fluorooxindoles from Hydrazonoindolin-2-one by Selectfluor

Efficient syntheses of 3,3-difluorooxindoles and 3-fluorooxindoles via fluorination of hydrazonoindolin-2-one with Selectfluor are reported. Under different solvent conditions, this method produced 3,3-difluorooxindoles and 3-fluorooxindoles selectively. The broad substrate scope and mild reaction conditions make this transformation a valuable method in drug discovery and development.