Chlorination of Pyrrolo[1,2‐ <i>a</i> ]quinoxalines Enabled by a Cyclic Iodine(III) Reagent and Its Application

ABSTRACT We have developed a highly efficient and regioselective method for the C─H chlorination of pyrrolo[1,2‐ a ]quinoxalines. Utilizing 1‐chloro‐1,2‐benziodoxol‐3‐one as a mild chlorinating reagent, this transformation proceeds at room temperature within 20 min, affording a wide range of C1‐chlorinated products in excellent yields without transition‐metal catalysts. The protocol features a broad substrate scope and excellent functional group tolerance. Its synthetic utility was demonstrated through gram‐scale synthesis and versatile derivatization of the chlorinated products via Suzuki–Miyaura reaction and other transformations, providing efficient access to diverse functionalized heterocycles.