Conversion of cyclic ketones to 2,3-fused pyrroles and substituted indoles.

A highly effective synthesis of 2,3-fused pyrroles from cyclic ketones has been achieved. The transformation includes a rhodium-catalyzed reaction of 4-alkenyl-1-sulfonyl-1,2,3-triazoles featuring an unusual 4π electrocyclization. The methodology was further extended to the synthesis of indoles using a one-pot reaction starting from 1-ethynylcyclohexenes.