Visible-light-promoted hydroxysulfenylation of alkenes for the synthesis of β-hydroxysulfides

Herein, we report a regioselective, visible-light-activated and base-catalyzed difunctionalized strategy for the preparation of β-hydroxysulfides from alkenes, thiols, and molecular oxygen (O₂). This one-pot, metal- and photocatalyst-free transformation offers an efficient and straightforward approach to access β-hydroxysulfides under environmentally-friendly conditions. This reaction features a broad substrate scope, excellent functional group tolerance, and good to excellent isolated yields (up to 94%), and uses molecular oxygen as a green oxidant, making it valuable for applications in synthetic organic chemistry. Detailed spectroscopic studies (such as UV-Vis, NMR, EPR, and HRMS analyses), along with several control experiments, provide a deeper mechanistic understanding of the transformation, thereby enhancing the significance of this work.