The reaction of azulenes with several sulfoxides in the presence of acid anhydrides to afford the corresponding 1-azulenylsulfonium and 1,3-azulenediyldisulfonium ions is reported. The subsequent conversion of these ions in high yields into 1-azulenyl methyl and phenyl sulfides and 1,3-bis(methyl- and phenylthio)azulenes through treatment with diethylamine is also described. Reaction of the 1-azulenyl sulfides with MCPBA afforded 1-azulenyl sulfoxides, which were then efficiently transformed into 1,1′-biazulene derivatives under acidic conditions. The redox properties of 1-azulenyl methyl and phenyl sulfides, 1,3-bis(methyl- and phenylthio)azulenes, and 1,1′-biazulene derivatives bearing methylthio or phenylthio substituents on each azulene ring are reported based on the results of cyclic voltammetry experiments.
- Cyclic voltammetry
- Electrophilic substitution