Wang Xiaojiao, Lei Bowen, Ma Lifang, Zhu Lisi, Zhang Xinyue, Zuo Hao, Zhuang Dailin, Li Ziyuan
Department of Pharmaceutical and Biological Engineering, School of Chemical Engineering, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu, 610065, China.
Chem Asian J. 2017 Nov 2;12(21):2799-2803. doi: 10.1002/asia.201701258. Epub 2017 Oct 13.
Direct C5-alkylation of oxazole/thiazole with ether or cycloalkane has been achieved through a cobalt-catalyzed cross-dehydrogenative coupling (CDC) process in moderate to good yields. This transformation represents the first C(sp )-C(sp ) cross-coupling at the C5-position of the oxazole/thiazole via double C-H bond cleavages. Various functional groups on oxazole/thiazole substrates, as well as water and air, are well-tolerated with this concise and practical protocol, constituting straightforward access to heterocycles with great medicinal significance. A preliminary mechanism involving a radical process has also been proposed.
通过钴催化的交叉脱氢偶联（CDC）过程，已实现恶唑/噻唑与醚或环烷烃的直接C5-烷基化反应，产率中等至良好。这种转化代表了通过双C-H键裂解在恶唑/噻唑的C5位上首次进行的C(sp³)-C(sp³)交叉偶联。该简洁实用的方法对恶唑/噻唑底物上的各种官能团以及水和空气都具有良好的耐受性，为具有重要药用意义的杂环化合物提供了直接的合成途径。还提出了一种涉及自由基过程的初步机理。
