PhSO2CF2H as a difluoromethylene bridge connecting electrophiles and electronically diverse alkenes.

The difluoromethylene (-CF2-) motif is highly valuable in pharmaceuticals, agrochemicals, and materials science due to its unique physicochemical properties. Herein, we present a broadly applicable strategy for the modular synthesis of CF2-containing compounds by using difluoromethylene to bridge electrophiles and electronically diverse alkenes, with difluoromethyl phenyl sulfone (PhSO2CF2H) as the difluoromethylene source. Central to this approach is the activation of (phenylsulfonyl)difluoromethylated derivatives (PhSO2CF2R) by the excited-state Hantzsch ester anion (HE-), which enables efficient generation of difluoroalkyl radicals under mild conditions. This method exhibits broad substrate scope, accommodating electron-rich, neutral, and deficient alkenes, as well as a wide range of difluoroalkyl sulfones derived from alkyl halides, cyclic sulfates, and carbonyl compounds. Furthermore, we developed a simplified operational protocol that circumvents the need for pre-preparation of PhSO2CF2R. Mechanistic studies support a radical pathway initiated by single-electron transfer between the photoexcited HE- and PhSO2CF2R. Practical applications are demonstrated through gram-scale syntheses and late-stage modification of bioactive molecules and functional materials, establishing a versatile platform for constructing a wide range of difluoromethylene-containing compounds.