Fe(III) @g-C3N4 nanocomposite-catalyzed green synthesis of di-indolyloxindole derivatives

A Fe(III)/g-C 3 N 4 nanocomposite was simply synthesized by impregnation of FeCl 3 with g-C 3 N 4 , and the heterogeneous nanocomposite was characterized by various techniques; including X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy. Then, the 3-indolylation reaction of isatin with indole derivatives was carried out in the presence of the Fe(III)/g-C 3 N 4 nanocomposite in water in reflux conditions. The results showed that the corresponding products were synthesized in excellent yields (up to 96%) in a short time (30 min). The significant features of this protocol are the non-toxic solvent, green media, short reaction time and high yields.