A green protocol for the synthesis of bis(indolyl)methanes catalyzed by succinic acid under microwave irradiation

An eco-friendly simple and efficient synthesis of 3,3’-bis(indolyl)methanes was carried out by electrophilic substitution reaction of indole with structurally divergent aldehydes by using succinic acid as green catalyst and water as green solvent under microwave irradiation. The advantages of this protocol are excellent yields, higher availability, inexpensive catalyst, lack of toxicity, shorter reaction time and more environmentally friendly catalyst. The reaction is chemoselective applicable only to aldehydes.