Synthesis of 5,7-diarylindoles Suzuki-Miyaura coupling in water.

The synthesis of novel 5,7-diaryl and diheteroaryl indoles has been explored efficient double Suzuki-Miyaura coupling. The method notably employs a low catalyst loading of Pd(PPh) (1.5 mol%/coupling) and water as the reaction solvent to obtain 5,7-diarylated indoles without using -protecting groups in up to 91% yield. The approach is also suitable for -protected and 3-substituted indoles and constitutes an important green and convenient arylation strategy for the benzenoid ring of indoles. The synthesized diarylindoles are fluorescent.