An efficient approach to 3-thioether-functionalized 2,3-dihydrobenzofurans via a metal-free intramolecular radical cyclization/thiolation cascade reaction

A diverse series of 3-thioether-functionalized 2,3-dihydrobenzofurans were prepared by an intramolecular radical cyclization/thiolation cascade reaction of alkenyl-tethered arenediazonium salts with thiophenols under transition-metal-free conditions. The mild and practical reaction conditions tolerated various functional groups and afforded the corresponding 2,3-dihydrobenzofurans in moderate to good yields.