Synthesis of Sulfonyl Fluorides from Sulfonamides.

A simple and practical synthesis of sulfonyl fluorides from sulfonamides is reported. The method capitalizes on the formation of the sulfonyl chloride by virtue of the reaction of Pyry‐BF4 and MgCl2, and subsequent in situ conversion to the more robust and stable sulfonyl fluoride by the presence of KF. The mild conditions and high chemoselectivity of the protocol enable the late‐stage formation of sulfonyl fluorides from densely functionalized molecules. [ABSTRACT FROM AUTHOR]