Direct fluorination of diarylacetylenes to diaryltetrafluoroethanes with convenient F2 equivalent nitrosonium tetrafluoroborate-pyridinium polyhydrogen fluoride

Nitrosonium tetrafluoroborate and pyridinium polyhydrogen fluoride (PPHF) reagent system function as F2 equivalent reagent in the direct one-step fluorination of diarylacetylenes to diaryltetrafluoroethanes. Fluorination of 1-phenyl-1-butyne by this system leads to the formation of 1-phenyl-1,1,2,2-tetrafluorobutane and 1-phenyl-1,1, 2-trifluoro-2-butene. Mechanistic study reveals the initial formation of NOF, followed by addition, protonation and nucleophilic displacement steps.