Visible-light-induced cyclization of 2-alkenyl-1,1′-biphenyls

Abstract

A novel and efficient method for the preparation of phenanthrene-9,9(10H)-dicarbonitrile derivatives has been developed, which occurs through the cyclization of 2-malononitrilemethylene-substituted 1,1’-biphenyls under metal-free conditions. The transformation involves photoelectrocyclization via...

Photoinduced Radical Cyclization of 2-Alkynylthioanisoles with Disulfides without an External Photocatalyst

“…To the best of our knowledge, the preparation of 3-phenylthiobenzo­[ b ]­thiophene was rarely reported . In continuation of our interests in visible-light photochemistry and inspired by the previous work, we wondered whether in situ-generated phenylthio radical via homolytic cleavage of phenyl disulfides could undergo the radical tandem cyclization with 2-alkynylthioanisoles as other radicals do, thus providing a direct and facile access to 3-arylthio­[ b ]­benzothiophenes. Notably, diphenyl disulfide and diphenyl diselenide have been widely used as sulfur or selenium sources in organic synthesis via a radical process .…”