Visible-light-Enabled O-Selective Radical Etherification of 1,2-Dicarbonyl Compounds for the Synthesis of Sterically Congested Ethers

<jats:p>A visible-light-promoted, triphenylphosphine-mediated protocol for the direct O-selective etherification of 1,2-diketones is reported. Using NHPI esters as radical precursors, this method provides an efficient route to sterically congested ethers under mild conditions. The strategy exhibits compatibility with various tertiary alkyl radicals and 1,2-diketone derivatives. Mechanistic studies support a radical-mediated pathway, and adaptation to a photochemical continuous-flow platform enables improved efficiency, scalability, and operational control.</jats:p>