Visible Light-Induced\n6π-Heterocyclization/Dehydroaromatization\nfor Synthesis of Indoloquinolinone Skeletons

In this work, we report a protocol\nfor the synthesis\nof an indoloquinolinone\nskeleton using visible light-induced energy transfer. This method\navoids the premodification of substrates and exhibits high yields.\nFor gram-scale reactions, only 0.01 mol % (100 ppm) of photosensitizer\nis required for rapid conversion. Mechanistic studies revealed that\nthis reaction differs from conventional 6π photocyclization\nreactions; undergoing a process involving 6π cyclization due\nto energy transfer and dehydrogenation due to product self-catalysis\nhas been experienced.