Acid Catalysis in the Aminium Hexachloroantimonate-Induced Cyclodimerization of 1-Aryl-1-phenylethylenes

Scope and limitations of the TEMPO/EPR method for singlet oxygen detection: the misleading role of electron transfer

“…To actually prove that an electron transfer reaction can contribute to the production of the TEMPO radical, TEMP was oxidized by tris(4-bromophenyl)aminium hexachloroantimonate (also named BAHA or magic blue), a known one-electron oxidizing agent (E red = 1.17 V vs SCE) [46]. Addition of BAHA to a solution of TEMP in acetonitrile led to the bleaching of the initial blue color, which turned pale brown ( Figure S7 in the Supplementary Material).…”

Aminium Hexachloroantimonate Salts as Latent Sources of Antimony Pentachloride in Pinacolic Rearrangement of Vicinal Diols

“…The different reaction rates observed in runs 11–12 and, in part, for the substrate 1a in runs 1–3 might be accounted for by the hypothesis that aminium salts, due to the capability of the aminium cation‐radical to oxidize the hexachloroantimonate anion (SbCl 6 – ),7,8 may effectively behave as latent sources of antimony pentachloride, as in Equation (1). …”

“…Proceeding with our interest in the reactivity of aminium salts A and B , we recently found that these salts may also release antimony pentachloride (SbCl 5 ), which might behave both as a one‐electron oxidising agent7 and as a Lewis acid,8 in relation to particular reaction conditions and properties of donor substrates.…”

Cycloreversion of Azetidines via Oxidative Electron Transfer. Steady-State and Time-Resolved Studies

“…Hence, the goal of the present work was to gain insight into the mechanistic aspects of azetidine CR via electron transfer. For this purpose 1,2,3-triphenylazetidines c - 2 and t - 2 were chosen as models and tris(4-bromophenyl)aminium hexachloroantimonate (also named BAHA or magic blue) as one-electron oxidizing agent.…”