Visible Light‐Induced Copper‐Catalyzed Alkylation/exo‐Cyclization of 1,7‐Dienes with Sulfonium Salts to Access Sulfur‐Containing Polycyclic Compounds

Abstract A direct visible‐light‐promoted radical‐triggered tandem cyclization of 1,7‐diene systems with cyclic sulfonium salts by using copper(I)‐based complexes as photoredox catalyst is developed. With this approach, a variety of sulfur‐containing polycyclic derivatives are prepared through alkylation/ 6‐exo‐trig cyclization/ 5‐exo‐trig cyclization of 1,7‐diene systems under mild conditions. In addition, the photoinduced copper‐catalyzed ring‐opening of cyclic sulfonium salts provides the alkyl radical intermediates, which prefers addition to the C−C double bond that connected to the aromatic ring rather than the electron‐deficient vinyl in 1,7‐dienes. Moreover, oxidation of the desired sulfur‐containing polycyclic products provides a strategy for the preparation of remote nitrogen‐fused polycyclic substituted sulfoxide or sulfone‐containing derivatives.