<i>N</i>‑Fluorosulfurylamidines Enable\nModular Synthesis of 1,5-Disubstituted Tetrazoles

Here we report the modular synthesis of 1,5-disubstituted\ntetrazoles\nusing two highly chemoselective reactions, ligations of <i>N</i>-fluorosulfurylamidines with amines and diazotransfer reactions between\nFSO<sub>2</sub>N<sub>3</sub> and <i>N</i>-monosubstituted\namidines, respectively. Enabled by sulfur(VI) fluoride exchange (SuFEx)\nclick chemistry, we have successfully synthesized a series of <i>N</i>-fluorosulfurylamidines and identified them as stable and\nscalable organic synthons. We then discover that <i>N</i>-fluorosulfurylamidines react selectively toward a series of aliphatic\namines, resulting in the formation of <i>N</i>-monosubstituted\namidines that can react further with FSO<sub>2</sub>N<sub>3</sub> to\ndeliver 1,5-disubstituted tetrazoles. Our work provides a new platform\nfor generating a library of 1,5-disubstituted tetrazoles with diverse\nstructures, which is unprecedented.