Chemoselective Reactions of Functionalized Sulfonyl Halides

Chemoselective transformations of functionalized sulfonyl fluorides and chlorides are surveyed comprehensively. It is shown that sulfonyl fluorides provide an excellent selectivity control in their reactions. Thus, numerous conditions are tolerated by the SO2F group - from amide and ester formation to directed ortho-lithiation and transition-metal-catalyzed cross-couplings. Meanwhile, sulfur (VI) fluoride exchange (SuFEx) is also compatible with numerous functional groups, thus confirming its title of "another click reaction". On the contrary, with a few exceptions, most transformations of functionalized sulfonyl chlorides typically occur at the SO2Cl moiety. Chemoselective reactions of sulfonyl halides bearing an additional functional group are reviewed. It is shown that sulfonyl fluorides can be tolerated in many chemical transformations and still undergo sulfur (VI) fluoride exchange (SuFEx) selectively. On the contrary, most reactions of functionalized sulfonyl chlorides typically proceed at the SO2Cl moiety, although there are notable exceptions.image