Valuable solvent of high polarity and low nucleophilicity: Tetrahedron Lett., 2335 (1974). Extremely powerful H bond donor but poor H bond acceptor: anions are highly solvated, but cations poorly. For feature article on the use of this unique solvent in the stabilization of radical cations, with particular application to EPR spectroscopy, see: Chem. Commun., 2105 (1996). Preferred solvent for the direct substitution of phenol ethers promoted by [Bis(trifluoroacetoxy)-iodo]benzene: Tetrahedron Lett., 32, 4321 (1991). The intermediacy of radical cations in this reaction has been demonstrated: J. Am. Chem. Soc., 116, 3684 (1994). See also: J. Org. Chem., 60, 7144 (1995). Powerful solvent for oligopeptides: Bull. Chem. Soc. Jpn., 61, 281 (1984); 66, 494 (1993). Lithiation generates the useful synthon lithium perfluoropropenolate: Org. Synth., 76, 151 (1998):
