An Air- and Moisture- stable Electrophilic Fluorinating Reagent

1-Fluoro-3,3-dimethyl-1,2-benziodoxole (1) is a hypervalent iodine derivative developed by Stuart et al.¹⁾ This compound is stable to air and moisture and used as an electrophilic fluorinating reagent for a α-monofluorination of β-ketoesters in the presence of triethylamine trihydrofluoride. In this reaction, a difluorination reaction occurs by increasing the amounts of 1 with heating at 60 °C.
On the other hand, Szabó et al. have reported a difluorination reaction of 1 with styrene derivatives.²⁾ They suggest that the reaction proceeds through the formation of a phenonium ion intermediate based on a deuterium-isotope-labelling experiment.