Kyungsoo Oh

A visible‐light‐induced selenocyclization of ortho ‐vinylanilides to 4 H ‐3,1‐benzoxazines has been developed under controlled O 2 atmosphere. The low O 2 content in reaction medium promotes the aerobic selenol oxidation to diselenides for the full use of 2 equiv. selenyl radicals in a redox‐neutral way, avoiding the aerobic oxidation of ortho ‐vinylanilides under higher O 2 content. The developed visible light‐induced selenocyclization of ortho ‐vinylanilides utilizes only visible light with low O 2 content, eliminating the use of exogenous photocatalyst and chemical oxidant.