Radical Alkynylthiolation\nwith Visible-Light-Sensitive <i>S</i>‑Alkynylthio\nSulfonates

A novel kind of <i>S</i>-alkynylthio sulfonate,\nwhich\ncan be directly activated under visible-light irradiation, has been\ndeveloped for the radical addition of multiple bond systems and radical\ncoupling with diazonium salts under photocatalyst-free conditions.\nThis strategy features a broad substrate scope, high regioselectivity,\nexcellent tolerance of functional groups, and the late-stage modification\nof drugs. Experimental and theoretical mechanistic investigations\ngave reasonable insight into the photolysis of <i>S</i>-alkynylthio\nsulfonates and C–S bond formation.