Okamoto Kazuhiro, Shida Naoki, Morizumi Haruka, Kitano Yoshikazu, Chiba Kazuhiro
Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan.
Department of Science and Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa, 240-8501, Japan.
Angew Chem Int Ed Engl. 2022 Jul 25;61(30):e202206064. doi: 10.1002/anie.202206064. Epub 2022 Jun 14.
Oxidative biaryl coupling of aryls with different electronic features generally fails. However, this has not been systematically studied via theoretical analysis, and thus, the crucial factor governing coupling efficiency remains unclear. Herein, we propose that the "oxidation potential gap (ΔE )" is a key parameter in predicting the efficiency of an intramolecular oxidative coupling reaction, with ΔE defined as a difference in the oxidation potentials of the relevant aromatic rings. Our experimental and computational analyses revealed that the efficiency of an aromatic intramolecular coupling reaction correlates with the activation energy (ΔE ) of C-C bond formation of the radical cation intermediates. Furthermore, ΔE correlates with ΔE . Therefore, we demonstrate the tuning of ΔE by attaching cleavable extra electron-donating/-withdrawing groups, enabling the rational synthesis of a phenanthridone skeleton using aromatic rings with an electronic gap.
具有不同电子特性的芳基之间的氧化联芳基偶联通常难以实现。然而，尚未通过理论分析对此进行系统研究，因此，决定偶联效率的关键因素仍不清楚。在此，我们提出“氧化电位差（ΔE）”是预测分子内氧化偶联反应效率的关键参数，其中ΔE定义为相关芳香环氧化电位的差值。我们的实验和计算分析表明，芳香族分子内偶联反应的效率与自由基阳离子中间体C-C键形成的活化能（ΔE）相关。此外，ΔE与ΔE相关。因此，我们证明了通过连接可裂解的额外供电子/吸电子基团来调节ΔE，从而能够使用具有电子间隙的芳香环合理合成菲啶酮骨架。
