Copper-Catalyzed\nRadical Sulfonylation: Divergent\nConstruction of C(sp<sup>3</sup>)‑Sulfonyl Bonds with Sulfonylhydrazones

Sulfonylhydrazones have been proven to be versatile synthetic\nintermediates\nin a panel of transformations. However, radical sulfonylation with\nsulfonylhydrazone as sulfonyl radical source is relatively rare. Here,\nwe found that sulfonylhydrazone can serve as a new sulfonyl radical\nprecursor to couple various partners such as arylacetic acids, ene–yne–ketones,\nand <i>para</i>-quinone methides under copper catalysis\nand microwave irradiation. The reactions of sulfonyl radicals have\nbeen successively developed to enable the divergent synthesis of C(<i>sp</i><sup>3</sup>)-sulfonyl bonds. In addition, when alkynes\nand alkenes are used as radical receptors, this method can also promote\nthe formation of C(<i>sp</i><sup>2</sup>)-sulfonyl bonds.\nThis finding suggests that sulfonylhydrazone could be regarded as\na potentially useful sulfonyl radical in sulfone synthesis.