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Updated: Apr 25, 2026

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives
Published on: January 19, 2016
Long-lived trifluoromethanide anion: a key intermediate in nucleophilic trifluoromethylations
G K Surya Prakash1, Fang Wang, Zhe Zhang
1Loker Hydrocarbon Research Institute, Department of Chemistry, University of Southern California, 837 Bloom Walk, Los Angeles, CA 90089-1661 (USA). gprakash@usc.edu.
Abstract:
The trifluoromethanide anion is the postulated key intermediate in nucleophilic trifluoromethylation reactions. However, for more than six decades, the trifluoromethanide anion was widely believed to exist only as a short-lived transient species in the condensed phase. It has now been prepared in bulk for the first time in THF solution. The trifluoromethanide anion with the [K(18-crown-6)](+) cation was unequivocally characterized by low-temperature (19)F and (13)C NMR spectroscopy. Its intermediacy in nucleophilic trifluoromethylation reactions was directly evident by its reaction chemistry with various electrophilic substrates. Variable-temperature NMR spectroscopy, along with quantum mechanical calculations, support the persistence of the trifluoromethanide anion.
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