Synthesis of mesoionic analogues of heptafulvene via dicationic ether salts derived from mesoionic olates and trifluoromethanesulphonic anhydride
Abstract
Three kinds of mesoionic analogues of heptafulvene have been synthesized by the base-induced reaction of active methylene compounds with the dicationic ether salts derived from mesoionic olates and trifluoromethanesulphonic anhydride. Based on their spectroscopic properties, it is shown that dipolar structures make an important contribution to the ground state of the synthesized fulvenes.