Transition‐Metal‐Free (Hetero)arylsulfonylation of 1‐Iodopyrrolo[1,2‐a]quinoxalines

We describe herein a method for transition‐metal‐free (hetero)arylsulfonylation of 1‐iodopyrrolo[1,2‐a]quinoxalines with sodium arylsulfinates. The corresponding aryl iodides were in situ prepared from eletrophilic iodination of C1−H bonds in pyrrolo[1,2‐a]quinoxalines with N‐iodosuccinimide. The ensuing sulfonylation only required DMSO as solvent and completed after 15 min. Many arylsulfinates bearing chloro, bromo, methylsufonyl, acetamide, and nitro groups were competent substrates. Heteroarylsulfonylation of pyrrolo[1,2‐a]quinoxalines were also feasible. A general method for transition‐metal‐free (hetero)arylsulfonylation of 1‐iodopyrrolo[1,2‐a]quinoxalines with sodium arylsulfinates is developed. A wide range of functionalities are tolerated. A possible mechanism is proposed.