Linkage Chemistry of S(VI) Fluorides

Sulfur(VI)-fluoride exchange linkage as a next generation of click chemistry was introduced by Sharpless and coworkers in 2014. Distinguished from CuAAC, the SuFEx reaction proceeds under metal-free conditions, and the reactive linkers are variable, enabling access to a diverse class of linkage compounds. Therein, a series of SuFEx linkers emerged has been widely prevalent in diverse fields. The S^VI -F bond in comparison to S^VI -Cl bond features excellent stability and chemoselectivity. The linkage chemistry primarily involves the formation of S-O and S-N bonds via commercially available phenols and amines, yet less study on C-SuFEx linkage. This review will focus on three types of linkage for SuFEx linkers comprising S-O, S-N, and S-C bonds, and we hope to provide a practical guidance for SuFEx linkage chemistry.