Synthesis and 18 F Labeling of Alkenyl Sulfonyl Fluorides via an Unconventional Elimination Pathway.

A successful Cu-catalyzed addition of both Cl and SO 2 OCF 2 H groups into alkenes allows us to discover the unusual reactivity of the SO 2 OCF 2 H group. As opposed to common sulfonic esters (RSO 2 -O-R'), in which the R' group is highly electrophilic, the SO 2 moiety demonstrates higher electrophilicity in RSO 2 -OCF 2 H. The unexpected reactivity is further developed not only as a synthetic tool for well-functionalized alkenyl sulfonyl fluorides but also for the first 18 F labeling of alkenyl sulfonyl fluorides.