Hypervalent Iodine Reagents: Thiol Derivatization with a Tetrafluoroethoxy Coumarin Residue for UV Absorbance Recognition

A new hypervalent iodine reagent ( 5 ) based on 1,2‐dihydro‐3,3‐dimethyl‐1,2‐benziodoxole containing a 4‐methyl‐7‐tetrafluoroethoxycoumarin unit as a specific UV absorber was prepared and fully characterized, including X‐ray crystal structural analysis. The high reactivity of this compound towards thiols has been exploited for the selective tagging of several targets with the UV chromophore coumarin, including e.g . glutathione.