Visible Light Driven α-Sulfonylation of Ketone-Derived Silyl Enol Ethers via Electron Donor-Acceptor Complex

The diverse utility of β-ketosulfones in pharmaceuticals and bioactive compounds has generated considerable interest in their synthesis. However, existing synthetic approaches often depend on transition-metal catalysts, which require extensive purification and low yields. Herein, we present a cost-effective, metal-, photocatalyst-free, visible light electron donor-acceptor (EDA) complex-mediated sulfonylation of ketone-derived silyl enol ethers with thiosulfonates (acceptor) and DABCO as an electron donor under mild conditions, offering a more efficient and straightforward approach. Our method enables the synthesis of a diverse range of β-keto sulfone derivatives, including biologically active and late-stage molecules, in good yields. Our strategy offers several significant advantages over existing techniques, which include (i) transition-metal and photoredox catalyst-free; (ii) external SO2-source-free; (iii) broad substrate scope; (iv) recyclable and reusable by-product; (v) excellent atom economy, reaction mass efficiency, process mass intensity, and E-factor and EcoScale scores, highlighting its efficiency and economic sustainability. Detailed mechanistic studies confirm the involvement of an EDA-complex mediated radical process that operates without a catalyst.