Institute for Advanced Studies, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, China.
Chem Commun (Camb). 2019 Feb 21;55(17):2489-2492. doi: 10.1039/c9cc00008a.
Thiourea dioxide as the source of sulfonyl groups for the efficient synthesis of heteroaryl sulfones and sulfonamides from heteroaryl halides under visible light irradiation is reported. This transformation proceeds smoothly via heteroaryl sulfinate intermediates, which can be trapped in situ by various electrophiles. A broad reaction scope is demonstrated, especially for the electron-deficient heteroaryl halides. Mechanistic studies show that the radical coupling of the heteroaryl radical and sulfur dioxide radical anion may be the key step during the reaction process, as supported by EPR spectroscopy and DFT calculations.
本文报道了二氧硫脲作为磺酰基源，在可见光照射下，从杂卤代芳烃高效合成杂芳基砜和砜酰胺。该转化通过杂芳基亚磺酸盐中间体顺利进行，这些中间体可以通过各种亲电试剂原位捕获。该反应具有广泛的适用范围，特别是对缺电子的杂卤代芳烃。机理研究表明，正如 EPR 光谱和 DFT 计算所支持的那样，杂芳基自由基和二氧化硫自由基阴离子的自由基偶联可能是反应过程中的关键步骤。
