title: Long-lived trifluoromethanide anion: a key intermediate in nucleophilic trifluoromethylations.
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.
authors.affiliation: Loker Hydrocarbon Research Institute, Department of Chemistry, University of Southern California, 837 Bloom Walk, Los Angeles, CA 90089-1661 (USA). gprakash@usc.edu.
authors.forename: G K Surya
authors.initials: GK
authors.lastname: Prakash
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhang
authors.forename: Ralf
authors.initials: R
authors.lastname: Haiges
authors.forename: Martin
authors.initials: M
authors.lastname: Rahm
authors.forename: Karl O
authors.initials: KO
authors.lastname: Christe
authors.forename: Thomas
authors.initials: T
authors.lastname: Mathew
authors.forename: George A
authors.initials: GA
authors.lastname: Olah
mesh_terms: D000838:Anions / Q000737:chemistry*; D005461:Fluorine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation
chemical_list: D000838:Anions; D005461:Fluorine
keywords: NMR spectroscopy; carbanions; fluorine; reaction mechanisms; reactive intermediates