1-Amino-2-nitroethene derivatives in triflic acid: NMR study and triflates formation from their hydroxynitrilium ions

Article abstract of DOI:10.1016/S0040-4020(99)00244-6

In triflic acid, 1-amino-2-nitroene derivatives undergo a C,O- diprotonation followed by the loss of (protonated) water, to form the >C=N < conjugated hydroxynitrilium ions that can react, in a competitive way, either with TfO or with added C₆H₆. The resulting phenylated dications can be selectively reduced by NaBH₄ at the iminium bond moiety. A protonated nitroso derivative was also isolated as its triflate salt. Structure, reactivity and mechanism of these reactions are discussed.