Shi Qiu, Huang Yu, Liu Wenbo H
School of Chemistry, Sun Yat-sen University, Guangzhou 510006, China.
Precis Chem. 2023 Apr 7;1(5):316-325. doi: 10.1021/prechem.3c00035. eCollection 2023 Jul 24.
Aromatic oxazolines are versatile in organic synthesis as directing groups, ligands, and protected carboxylic acids. Developing efficient approaches to oxazoline from an aromatic C-H bond is more desirable compared to the established protocols from carboxylic acid and its equivalents. Herein, a simple and efficient aromatic C-H oxazolination with broad substrate scope is described. By employing this transformation as an enabling step, diversity-oriented synthesis of functionalized arenes and target-oriented synthesis of four drugs were accomplished. Mechanistic experiments suggest that this aromatic oxazolination is an electrophilic aromatic substitution. It is anticipated that this transformation will find applications in aromatic C-H functionalization with oxazoline either as a removable directing group or as a masked carboxylic acid.
芳香恶唑啉在有机合成中作为导向基团、配体和保护的羧酸具有多种用途。与从羧酸及其等价物出发的既定方法相比，开发从芳香碳氢键高效合成恶唑啉的方法更具吸引力。本文描述了一种底物范围广泛的简单高效的芳香碳氢键恶唑啉化反应。通过将此转化作为一个关键步骤，实现了功能化芳烃的多样性导向合成以及四种药物的目标导向合成。机理实验表明，这种芳香恶唑啉化反应是亲电芳香取代反应。预计这种转化将在以恶唑啉作为可去除导向基团或掩蔽羧酸的芳香碳氢键官能化中得到应用。
