Photo-induced tandem cyclization of unsaturated amides with thiocyanates to access thiocyanated heterocycles

Photo-induced two-radical thiocyanation cyclization systems of N-acryloyl aldehyde hydrazones/unsaturated coumarins with thiocyanate were completed, efficiently producing diverse thiocyanated pyrazolones/polycyclic coumarins with good selectivity. Meanwhile, various control experiments (scaled-up operations, substituent transformations, and radical capture/light-on-off operations) explored the merits and the plausible cyclization process of the thiocyanation systems.