Synthesis of 1-Arylsulfonyl Pyrrolo[1,2-A]quinoxalines: Scope and Limitation

We report herein a method for the synthesis of 1-arylsulfonyl pyrrolo[1,2-a]quinoxalines. The process included electrophilic iodination with N-iodosuccinimide of pyrrolo[1,2-a]quinoxalines and a copper-catalyzed sulfonylation with sodium aryl sulfinates. An array of functionalities including ester, nitro, and ketone groups are tolerated under reaction conditions. Two possibilities to rationalize the mechanism for sulfonylation are considered.