Catalyst-Controlled Divergent Cycloisomerizations of -Propargyl Indoles.

Herein, a new series of catalyst-controlled divergent cycloisomerizations of indole-tethered alkynes was developed utilizing readily available, versatile, and flexible -propargyl indoles as substrates and BrettPhosAuNTf and PtCl as catalysts, where the chemodivergency was attributed to both the steric and electronic nature of the catalysts. A broad spectrum of -propargyl indoles could be employed in this protocol, enabling the divergent synthesis of a library of 9-pyrrolo[1,2-]indoles and 4-pyrrolo[3,2,1-]quinolines. Moreover, the reactions could be performed at mmol scales.