From S-Fluoroalkylation to Fluoroalkylation–Thiolation: Difunctionalization of Alkenes with Fluoroalkyl Phenyl Sulfones and Thiophenols Enabled by Photoredox Copper Catalysis

Molecules containing fluoroalkyl and arylthio groups play a pivotal role in pharmaceutical and agrochemical development. The simultaneous introduction of these functional groups through the 1,2-difunctionalization of alkenes is an efficient strategy. Fluoroalkyl phenyl sulfones serve as accessible fluoroalkyl radical precursors; however, their tendency to interact with thiophenol via the electron donor-acceptor interaction mechanism can impede the desired transformation. Through meticulous selection of solvent and base, we successfully utilized copper catalysis to facilitate an alkene-involved three-component reaction. Our work unveils a photoredox copper-catalyzed fluoroalkylation-thiolation of alkenes using various fluoroalkyl phenyl sulfones (such as perfluoroethyl, tetrafluoroethyl, trifluoromethyl, difluoromethyl, difluoroalkyl, and difluorobenzyl). The efficacy of this approach is exemplified by the synthesis of Kengreal derivatives.