Synthesis of sulfone-functionalized chroman-4-ones and chromans through visible-light-induced cascade radical cyclization under transition-metal-free conditions†
Abstract
A highly efficient and straightforward approach has been developed for selective intramolecular radical cyclization of arylsulfinic acids with o-(allyloxy)arylaldehydes, o-(homoallyloxy)arylaldehydes and (but-3-en-1-yloxy)benzenes. This photoinduced reaction generated sulfone-functionalized chroman-4-ones and chromans in good to excellent yields under simple and mild conditions without an external photocatalyst.