A Green and Convenient Approach for the Synthesis of Indole-acrylonitrile and Indole-coumarin Hybrids in Aqueous Media

Indole–acrylonitrile hybrids were synthesized via a catalyst-free reaction of aromatic aldehydes and 3-(cyanoacetyl)indole in aqueous media. Also, indole-coumarin hybrids were synthesized via a domino reaction of salicylaldehyde derivatives and 3-(cyanoacetyl)indole in the presence of ammonium acetate in aqueous media. The advantages of the present protocol are high yields, short reaction times, mild reaction conditions, operational simplicity, and environmentally benign, and also there is no need to purification of products.