Group-assisted purification chemistry principles to access highly substituted zwitterionic furans via fast, concise, and efficient one-pot three-component assembly

Novel highly substituted zwitterionic furans were generated through the in situ formation of phosphonium salts. Firstly, intermediate salts were obtained via nucleophilic attack of Huisgen zwitterion to 3-cyanochromones. Finally, these intermediate salts underwent a proton migration, intramolecular cyclization, and ring-opening reaction to convert to the target products. The synthesized furans could be easily purified without traditional purification techniques (chromatography and recrystallization).