Some syntheses using tetrakis(trifluoromethyl)dewar thiophene

Tetrakis(trifluoromethyl)Dewar thiophene ($\text{1}$) is found to be a good dipolarophile and dienophile. Therefore, $\text{1}$ reacts with any kind of azides to give 1,3-dipolar cycloadducts, which are transformed to tetrakis(trifluoromethyl)Dewar pyrroles ($\text{2}$), compounds of a new cyclic ring system. Further, $\text{1}$ reacts with cyclic or acyclic dienes to give Diels-Alder adducts. The adduct ($\text{3}$) of $\text{1}$ with butadiene was transformed to tetrakis(trifluoromethyl)cyclooctatetraene ($\text{4}$) by desulfurization, bromination and dehydrobromination, stepwise. Valence-bond isomerisation of $\text{4}$ will be presented.