Formal α-Nucleophilic Addition to Electron-Deficient Alkenes by Photoredox and Copper Dual Catalysis

Difunctionalization of olefins provides an efficient method for the construction of complex molecules. However, direct nucleophilic addition at the α-carbon of α,β-unsaturated olefins is relatively sluggish due to an electronic mismatch. Here, we report a synergetic photoredox/copper system to achieve sulfonylation of electron-deficient alkenes via a SO₂-insertion strategy. With this approach, a wide range of sulfonyl-substituted lactone derivatives are synthesized under mild conditions with a broad substrate scope and good functional group compatibility.