Visible-Light-Induced Mpg-C3N4 Catalyzed C(sp2)−H Thiocyanation of Ketene Dithioacetals

Graphical Using mesoporous graphitic carbon nitride (mpg-C 3 N 4 ) as a metal-free heterogeneous photocatalyst was developed for thiocyanation of alkenes under visible light irradiation with oxygen as green oxidant and without any other additives. The present protocol has excellent functional group tolerance and the desired tetrasubstituted alkenyl thiocyanides were obtained in moderate to good yields. Moreover, the recyclable mpg-C 3 N 4 catalyst could be used at least 6 times without significant loss of activities. Using mesoporous graphite carbon nitride (mpg-C 3 N 4 ) as metal-free heterogeneous catalyst, the thiocyanation of ketene dithioacetals was achieved under visible light irradiation with oxygen as green oxidant and without any other additives. The present protocol has excellent functional group tolerance and the desired tetrasubstituted alkenyl thiocyanides were obtained in moderate to good yields. Moreover, the recyclable mpg-C 3 N 4 catalyst could be used at least 6 times without significant loss of activities. A series of mechanistic validation experiments indicated that the reaction involves a radical process.