Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai 200438, China.
School of Petrochemical Engineering, and Jiangsu Province Key Laboratory of Fine Petrochemical Engineering, Changzhou University, Changzhou 213164, China.
Chem Commun (Camb). 2018 Jul 11;54(54):7459-7462. doi: 10.1039/c8cc03465f. Epub 2018 Jun 18.
C-H bond sulfonylation of anilines with the insertion of sulfur dioxide under metal-free conditions is described. 2-Sulfonylanilines are generated in moderate to good yields through a three-component reaction of anilines, DABCO·(SO), and aryldiazonium tetrafluoroborates under mild conditions. No metal catalysts or additives are needed for this transformation. This direct C-H functionalization is highly efficient, and broad functional group tolerance is observed. A radical process is believed to be involved. In the reaction process, the arylsulfonyl radical and the tertiary amine radical cation generated in situ from DABCO·(SO), and aryldiazonium tetrafluoroborate are the key intermediates. Additionally, the tertiary amine radical cation acts as the electron carrier through a single electron transfer process.
本文描述了在无金属条件下二氧化硫插入芳基胺 C-H 键磺酰化反应。在温和条件下，通过苯胺、DABCO·(SO)和芳基重氮四氟硼酸盐的三组分反应，以中等至良好的收率生成 2-磺酰基苯胺。该转化不需要金属催化剂或添加剂。这种直接 C-H 官能化反应具有高效性，且观察到广泛的官能团容忍性。该反应过程中涉及自由基反应历程。在反应过程中，DABCO·(SO)和芳基重氮四氟硼酸盐原位生成的芳基磺酰基自由基和叔胺自由基阳离子是关键中间体。此外，叔胺自由基阳离子通过单电子转移过程充当电子载体。
