Gold-catalyzed tandem reaction in water: an efficient and convenient synthesis of fused polycyclic indolesElectronic supplementary information (ESI) available: 1H and 13C NMR spectra. See DOI: 10.1039/c2gc35293a

This report describes the gold-catalyzed synthesis of fused polycyclic indoles from substituted 2-(1 H -indol-1-yl) alkylamines and alkynoic acids in water under microwave irradiation. This protocol proceeds in high atom economy and leads to the generation of two rings, together with the formation of one new C-C bond and two new C-N bonds in a single operation. The advantages of the method include a short reaction time, excellent yield, easy work-up, and the use of microwave irradiation and an environmentally benign solvent. This "on water" protocol proceeds in high atom economy and leads to the generation of two rings, together with the formation of one new C-C bond and two new C-N bonds in a single operation.