Synthesis of sulfone-functionalized chroman-4-ones and chromans through the visible-light-induced cascade radical cyclization under transition-metal-free conditions

A highly efficient and straightforward approach for selective intramolecular radical cyclization of arylsulfinic acids and o-(allyloxy)arylaldehydes has been developed. This photoinduced reaction generated the sulfone-functionalized chroman-4-ones and chromans in good to excellent yields under simple and mild conditions without an external photocatalyst.