Abstract: | The reactions of p-trifluoromethylphenyllithium with 2,4,6-triarylthiopyrylium perehlorates (Ar = Ph, p-CH3OC6H4, p-NMe2C6H4) have been studied. The initially formed thiabenzenes were not slable enough to he isolated and rearranged readily to their corresponding 4-(p-tri-fluoromethylphenyl)-2,4,6-triarylthiopyrans. The instability of the intermediate thiabenzenes reveals that, in contrast to the stabilization effect of the electron-withdrawing p-chloro- and pentalluorophcnyl groups attached to carbon atoms in sulfur ring, the electron-withdrawing p-lrilluoromethyl group on subsliluenls attached to sulfur decreases the stability of thiabenzenes. |