Electrochemical Cascade Cyclization for Selenobenzothiophenes: Synthesis, Photochemistry, and Bioactivity

A mild and highly efficient metal‐ and oxidant‐free electrochemical approach for the synthesis of 3‐selenylated benzothiophene derivatives is described. In this innovative electrochemical cascade cyclization reaction, the selenylated benzothiophene skeletons can be constructed along with the formation of CSe and CS bonds in a single step. Moreover, this electrochemical protocol exhibits good functional group compatibility, paving the way for the construction of diverse selenylated benzothiophene compounds with various functional groups from readily available starting materials under an aerobic reaction condition. Meanwhile, a series of control experiments are carried out, and a reasonable reaction mechanism is proposed. Finally, the scaled‐up reactions are performed, and then the photochemical and bioactive properties of the synthesized compounds are elaborately discussed.