A first example of generating aryl cations in the solvolysis of aryl triflates in trifluoroethanol

CF Activation of Fluorobenzene by Silylium Carboranes: Evidence for Incipient Phenyl Cation Reactivity

“…[7,8] S N 1-like processes involving ArÀX substrates in solution are therefore rare and have only been accomplished with leaving groups such as N 2 + in diazonium salts and/or highly activated aryl moieties. [9,10] Even in these cases, substitution reactions probably proceed via a loose S N 2 Ar path or radical intermediate rather than a purely dissociative cationic mechanism. [11] Recent investigations into photochemically generated RC 6 H 4 + intermediates have shed light on the reactivity and synthetic utility of aryl cations in the (p) 5 (sp 2 ) 1 triplet state.…”

Copper-Free Halodediazoniation of Arenediazonium Tetrafluoroborates in Deep Eutectic Solvents-like Mixtures

“…Additionally, attempts to observe the formation of phenyl cations by ionization of aryl triflates have only succeeded when especially stabilizing groups, such as trimethylsilyl groups, are present at the 2- and 6-positions of the aromatic ring [ 51 ]. Moreover, the experiments that prove the existence of the phenylium have all been performed in an ionizing but almost non-nucleophilic solvent such as 2,2,2-trifluoroethanol.…”

Photochemical Generation and Reactivity of Naphthyl Cations: cine Substitution

“…β-Silicon-stabilized phenyl cations, generated from their triflate in trifluoroethanol, do not yield products derived from fluoride abstraction. [16] Remarkably, the iodonium tetrafluoroborate salts 1 and 2 do not yield the naphthyl fluorides 8-F and 12-F, whereas the diazonium tetrafluoroborate salts 1-N 2 + and 2-N 2 + do (see Schemes 2 and 4 vs. Scheme 6). We suggest that in the (polar) nucleophilic solvents used, the iodonium salts form diaryl-λ 3 -iodane complexes with the solvent: [Ar-I-Ph·solvent] + BF 4 -.…”