Germyl Radical Cyclization of Enynes and Dienes under Visible-Light Irradiation.

A visible-light-induced cyclogermylation of 1,6-enynes has been developed for the construction of germanium-containing heterocycles. Utilizing germanes and structurally diverse enynes or dienes as substrates, this protocol employs a synergistic dual catalytic system combining photoredox catalysis with hydrogen atom transfer (HAT). This strategy enables a radical-mediated hydrogermylation/cyclization cascade under mild conditions, featuring high reactivity and a broad substrate scope. Notably, this method not only allows for the synthesis of five-membered carbagermanes but also provides efficient access to nitrogen-containing (e.g., pyrrolidine) and oxygen-containing (e.g., tetrahydrofurans) organogermanium heterocycles in good yields.