Joy Muthipeedika Nibin, Kovalev Igor S, Shabunina Olga V, Santra Sougata, Zyryanov Grigory V
Ural Federal University named after the first President of Russia B. N. Yeltsin, 19 Mira Street, Yekaterinburg 620002, Russia.
I. Ya. Postovskiy Institute of Organic Synthesis, Ural Division of the Russian Academy of Sciences, 22 S. Kovalevskoy Street, Yekaterinburg 620219, Russia.
Antioxidants (Basel). 2024 Oct 3;13(10):1198. doi: 10.3390/antiox13101198.
A series of 16 (hetero)aryl compounds based on coumarin and equol has been efficiently synthesized by exploring the palladium-catalyzed Suzuki cross-coupling reactions. Polyphenol based on coumarin (4-methyl-7-hydroxy coumarin) was initially converted to corresponding coumarin imidazylate and then subjected to Suzuki coupling reaction with 4-methoxyphenylboronic acid to obtain the coupled product. This modified approach was later developed into a one-pot methodology by directly reacting the polyphenol with 1,1-sulfonyldiimidazole (SDI) and boronic acid in situ to obtain the Suzuki coupled product in one step. Moreover, an array of (poly)phenols based on coumarin and equol were later converted to diverse (hetero)aryl compounds by this optimized step-economic protocol. The synthesized compounds were then subjected to the screening of their potential antioxidant activities by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. In our investigation, the compounds , , and exhibited promising antioxidant potential when compared to the reference standard, butylated hydroxytoluene (BHT). Structure activity relationship (SAR) studies revealed the importance of the presence of electron-donating substituents in enhancing the antioxidant activity of the synthesized compounds.
通过探索钯催化的铃木交叉偶联反应，高效合成了一系列基于香豆素和雌马酚的16种（杂）芳基化合物。基于香豆素（4-甲基-7-羟基香豆素）的多酚最初转化为相应的香豆素咪唑酸盐，然后与4-甲氧基苯硼酸进行铃木偶联反应，得到偶联产物。后来，这种改进的方法发展成为一种一锅法，通过使多酚与1,1-磺酰二咪唑（SDI）和硼酸原位直接反应，一步获得铃木偶联产物。此外，一系列基于香豆素和雌马酚的（聚）酚后来通过这种优化的步骤经济方案转化为各种（杂）芳基化合物。然后通过2,2-二苯基-1-苦基肼（DPPH）测定法对合成的化合物进行潜在抗氧化活性的筛选。在我们的研究中，与参考标准丁基化羟基甲苯（BHT）相比，化合物 、 、 和 表现出有前景的抗氧化潜力。结构活性关系（SAR）研究揭示了供电子取代基的存在对增强合成化合物抗氧化活性的重要性。
