Changmei Zhang, Yan He, Heping Tan, Yang He, Danqing Zheng
Despite the importance of sulfoxides in synthesis and biology, the utilization of sulfinyl radicals for their construction remains underexplored compared to other sulfur-centered radicals. While the Persistent Radical Effect (PRE) offers a powerful framework to harness these stabilized species for radical–radical cross-coupling, the development of general transformations is rare due to the lack of modular sulfinyl radical precursors. Herein, we report N -sulfinyl phthalimides as bench-stable, modular precursors that selectively liberate persistent sulfinyl radicals upon single-electron reduction. This strategy enables the first general 1,2-trifluoromethyl-sulfinylation of unactivated alkenes and robust PRE-guided cross-couplings with diverse alkyl radicals derived from C–H bonds, Hantzsch esters, or carboxylic acids. Furthermore, we report the first generation of unsymmetrical sulfinyl sulfones and elucidate a mechanism driven by their rapid tautomerization, enabling a catalyst-free, ambient-temperature protocol for the direct conversion of sulfinate salts into sulfoxides. The broad utility of these protocols is demonstrated by the successful difunctionalization of ethylene gas and the late-stage modification of complex medicinal compounds, alongside versatile product derivatizations. This work establishes a versatile platform for radical sulfinylation governed by precise kinetic control.