Wang Xuefeng, Yang Min, Xie Wenlin, Fan Xiaona, Wu Jie
Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai 200438, China.
Gannan Medical University Collaborative Innovation Center for Gannan Oil-tea Camellia Industrial Development, 1 Yixueyuan Road, Ganzhou 341000, China.
Chem Commun (Camb). 2019 May 28;55(43):6010-6013. doi: 10.1039/c9cc03004b. Epub 2019 May 7.
A sulfonylation reaction of 4-substituted Hantzsch esters, DABCO·(SO), and electron-deficient alkenes at room temperature in the presence of photoredox catalysis under visible light irradiation is described. Not only (E)-chalcones but also (vinylsulfonyl)benzene and 2-vinylpyridine are all suitable substrates in the transformation. This sulfonylation reaction under mild conditions shows a broad substrate scope with a good functional group compatibility. A plausible mechanism is proposed, which shows that the 4-substituted Hantzsch esters would be radical reservoirs under photoredox catalysis. The alkyl radical generated in situ from the 4-substituted Hantzsch ester would be trapped by sulfur dioxide to produce an alkylsulfonyl radical, which would then undergo further transformation leading to the final outcome.
描述了在可见光照射下，4-取代的汉茨希酯、DABCO·(SO)和缺电子烯烃在光氧化还原催化作用下于室温下进行的磺酰化反应。不仅（E）-查尔酮，而且（乙烯基磺酰基）苯和2-乙烯基吡啶都是该转化反应中的合适底物。这种在温和条件下的磺酰化反应显示出广泛的底物范围和良好的官能团兼容性。提出了一种合理的机理，表明4-取代的汉茨希酯在光氧化还原催化下将作为自由基储存体。由4-取代的汉茨希酯原位产生的烷基自由基会被二氧化硫捕获生成烷基磺酰基自由基，然后该自由基会进一步转化导致最终产物的生成。
