Water- and organic-soluble reagent developed by R. E. Banks and co-workers for electrophilic fluorination of a variety of substrates under mild conditions: USP 5,086,178 (1992 to Air Products & Chemicals, Inc.); review: J. Fluorine Chem., 87, 1 (1998). In acetonitrile, activated aromatics can be fluorinated in good yield: J. Chem. Soc., Perkin 1., 2069 (1996). Less active substrates can be fluorinated in the presence of triflic acid: Israel J. Chem., 39, 207 (1999). In acetonitrile, vinylsilanes undergo fluorodesilylation to give vinyl fluorides with retention of configuration: Chem. Commun., 233 (2001). Stabilized carbanions can be selectively mono- or difluorinated: J. Chem. Soc., Chem. Commun., 343 (1994); Tetrahedron, 51, 3587 (1995). Fluorinated steroids have been prepared from enol acetates or silyl enol ethers: J. Org. Chem., 58, 2791 (1993).
