-Fluorosulfurylamidines Enable Modular Synthesis of 1,5-Disubstituted Tetrazoles.

Here we report the modular synthesis of 1,5-disubstituted tetrazoles using two highly chemoselective reactions, ligations of -fluorosulfurylamidines with amines and diazotransfer reactions between FSON and -monosubstituted amidines, respectively. Enabled by sulfur(VI) fluoride exchange (SuFEx) click chemistry, we have successfully synthesized a series of -fluorosulfurylamidines and identified them as stable and scalable organic synthons. We then discover that -fluorosulfurylamidines react selectively toward a series of aliphatic amines, resulting in the formation of -monosubstituted amidines that can react further with FSON to deliver 1,5-disubstituted tetrazoles. Our work provides a new platform for generating a library of 1,5-disubstituted tetrazoles with diverse structures, which is unprecedented.