Cu-Catalyzed one-pot synthesis of thiochromeno-quinolinone and thiochromeno-thioflavone via oxidative double hetero Michael addition using in situ generated nucleophiles

A copper catalyzed three-component synthesis of pi-conjugated tetracyclic thiochromeno-quinolinone and thiochromeno-thioflavone was establishedviaoxidative double hetero Michael addition usingin situgenerated nucleophiles. Xanthate plays a dual role as an odourless sulfur source and a chemoselective reducing agent. Thein situformed iodine plays a crucial role in the oxidation step.