Description Application 1,2-Dibromoethane-1-sulfonyl fluoride (DESF) is a bench-stable precursor to 1-bromoethene-1-sulfonyl fluoride (BESF), a new and robust connective hub for the Sulfur (VI) fluoride exchange (SuFEx) click reaction. BESF offers similar routes as ethenesulfonyl fluoride (ESF, cat# 746959) but with additional reactivity due to the embedded bromo group. Treatment of DESF with triethylamine generates BESF in situ, which has been used to synthesize diverse and unprecented sulfonyl fluorides in good-to-excellent yields. As the resulting molecules possess sulfonyl fluoride handles, further SuFEx reactions are also possible. DESF adds another useful tool for conjugation strategies in chemical biology and organic and polymer synthesis. Other Notes 1-Bromoethene-1-sulfonyl fluoride (BESF) is another good connective hub for SuFEx click chemistry Regioselective Synthesis of Fluorosulfonyl 1,2,3-Triazoles from Bromovinylsulfonyl Fluoride Technology Spotlight: SuFEx: Sulfonyl Fluorides that Participate in the Next Click Reaction