A novel and efficient synthesis of 3-fluorooxindoles from indoles mediated by Selectfluor

[reaction: see text] Treatment of several 3-substituted indoles, including derivatives of tryptophan and serotonin, with commercially available Selectfluor in acetonitrile/water furnished 3-substituted 3-fluorooxindoles in good to high yields. Since 3-fluorooxindoles obtained are sterically similar to both oxindoles and 3-hydroxyoxindoles, they should be useful as probes for investigating the enzymatic mechanism of indole biosynthesis and metabolism.