Ai Liankun, Ajibola Ibrahim Yusuf, Li Baolin
School of Chemical Sciences, University of Chinese Academy of Sciences Beijing 100049 P. R. China
RSC Adv. 2021 Nov 10;11(57):36305-36309. doi: 10.1039/d1ra06985c. eCollection 2021 Nov 4.
An efficient method to synthesize benzothieno[3,2-]benzofurans intramolecular dehydrogenative C-H/O-H coupling has been developed. Good to excellent yields (64-91%) could be obtained no matter if the substituted group is electron-donating or electron-withdrawing. Notably, three-to-six fused ring thienofuran compounds could be constructed using this method. A reaction mechanism study showed that 1,1-diphenylethylene can completely inhibit the reaction. Therefore, it is a radical pathway initiated by single electron transfer between the hydroxyl of the substrate and the copper catalyst.
已开发出一种通过分子内脱氢C-H/O-H偶联合成苯并噻吩并[3,2 - ]苯并呋喃的有效方法。无论取代基是供电子的还是吸电子的，都能获得良好至优异的产率（64 - 91%）。值得注意的是，使用该方法可以构建三至六元稠环噻吩并呋喃化合物。反应机理研究表明，1,1 - 二苯乙烯可以完全抑制该反应。因此，这是一条由底物羟基与铜催化剂之间单电子转移引发的自由基途径。
