Dual Nickel/Photoredox-Catalyzed Arylsulfonylation of Allenes
Yu Zhou, Wenhui Yang, Nan‐Nan Dai, Jia-Yao Feng, Mingqi Yang, Wenqing Gao, Qiang Li, Chao Deng, Zhan Lu, Wen‐Ting Wei
Abstract
The nickel/photoredox dual catalysis system is an efficient conversion platform for the difunctionalization of unsaturated hydrocarbons. Herein, we disclose the first dual nickel/photoredox-catalyzed intramolecular 1,2-arylsulfonylation of allenes, which can accurately construct a C(sp 2 )–C(sp 2 ) bond and a C(sp 3 )–S bond. The reaction exhibits excellent chemoselectivity and regioselectivity, allowing modular conformations of a diverse series of 3-sulfonylmethylbenzofuran derivatives. Control experiments showed that the bipyridine ligand is crucial for the formation of a stable σ -alkyl nickel intermediate, providing the possibility for sulfonyl radical insertion. Meanwhile, the electrophilic sulfonyl radical facilitates further oxidative addition of the σ -alkyl nickel intermediate and inhibits addition with allenes. In addition, control experiments, cyclic voltammetry tests, Stern–Volmer experiments, and density functional theory calculations afford evidence for the Ni(0)/Ni(I)/Ni(II)/Ni(III) pathway in this 1,2-arylsulfonylation.