A clean and efficient synthesis of 5-(2′-fluoro-2′,3′-dimethylbutan-3′-yl) substituted 1,2,4-oxadiazoles using silver tetrafluoroborate as a fluorodesulfurization reagent

5-Ethylthio-6,6,7,7-tetramethyl substituted 4-oxa-1,3-diazabicyclo[3.2.0]hept-2-enes undergo fluorodesulfurization with silver tetrafluoroborate to furnish high yields of 5-(2′-fluoro-2′,3′-dimethylbutan-3′-yl) substituted 1,2,4-oxadiazoles. Ethylthio substituted 1,2,4-triaza- and 1,3-diaza-bicyclo[3.2.0]hept-2-enes behave in a similar fashion to yield 5-(2′-fluoro-2′,3′-dimethylbutan-3′-yl) substituted 1,2,4-triazoles and imidazoles, respectively.