Sulfonyl fluorides are covalent probes for enzyme binding sites and assess functionally important protein residues. They possess desirable electrophilicity that enables capture of context specific amino acid reactivity whilst retaining appropriate aqueous stability commensurate with biomolecular experiments. Sulfonyl fluoride electrophiles target active serine, threonine, tyrosine, lysine, cysteine and histidine residues.[1,2]
 Narayanan et al. (2015) Sulfonyl fluorides as privileged warheads in chemical biology. Chem. Sci. 6:2650.
 Dong et al. (2014) Sulfur(VI) fluoride exchange (SuFEx): another good reaction for click chemistry. Angew. Chem. Int. Ed. Engl. 53(36):9430.