SuFEx Reactions of Sulfonyl Fluorides, Fluorosulfates, and Sulfamoyl Fluorides Catalyzed by N‑Heterocyclic Carbenes

Sulfur(VI)
fluoride exchange (SuFEx) click chemistry provides a
powerful tool for the rapid assembly of modular connections. Herein,
we report an organocatalytic SuFEx reaction of sulfonyl fluorides,
fluorosulfates, and sulfamoyl fluorides. Under the catalysis of 10
mol % N-heterocyclic carbene (NHC), or under the relay catalysis of
NHC and HOBt, different SuFExable hubs efficiently undergo click reactions
with alcohols or amines to afford sulfonates, sulfonamides, sulfates,
sulfamates, and sulfamides in 49–99% yields. More than 190
sulfonylated products, including 25 natural product derivatives, have
been prepared through this method. Mechanism study showed that NHCs
might act as a carbon-centered Broønsted base to activate alcohols
or amines through the formation of hydrogen bonding.