Rhodium (II)-catalyzed synthesis of tetracyclic 3, 4-fused indoles and dihydroindoles

Abstract

An efficient synthetic method of tetracyclic 3, 4-fused indoles and dihydroindoles via rhodium-catalyzed (3+2) cycloaddition of N-tosyl-4-(2-phenoxyphenyl)-1, 2, 3-triazole was described. The aromatized xanthene derivatives can be achieved in a one-pot synthesis starting from 1-ethynyl-2-phenoxybenzene. The xanthene-based fused heterocycles were considered as the valuable fluorophore.