I 2 -Induced Selenation/Annulation Reaction of N -(2-Vinyl)phenylindoles to Assemble Seleno-Indolo[1,2- a ]indole Derivatives

A simple and efficient synthetic route to the I₂-promoted tandem annulation of N-(2-vinyl)phenylindoles and diaryl diselenides has been developed for the preparation of seleno-indolo[1,2-a]indole derivatives. Research has shown that iodine is an important reagent for triggering reactions and plays a crucial role in the reaction process. This reaction represents the first example of selenation reaction of 3-methyl-N-(2-vinylphenyl)-1H-indoles and diaryl diselenides under air conditions. Moreover, the reaction features a wide substrate scope, good group tolerance, and a low-cost iodine reagent, which provides a valuable strategy for the synthesis of polycyclic indole skeletons.