Catalyst-Controlled Divergent Cycloisomerizations of N -Propargyl Indoles.

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