Yang Jing-Wei, Ran Chuan-Kun, Zhu Wen-Jing, Jiang Yi, Yan Si-Shun, Ye Jian-Heng, Yu Da-Gang
Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China.
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
J Org Chem. 2025 Jun 20;90(24):8406-8412. doi: 10.1021/acs.joc.5c01091. Epub 2025 Jun 5.
Although significant progress has been made in achieving site-selective C-O bond functionalization in specific substrates, the selective cleavage and functionalization of C(sp)-O bonds in ethers remain a fundamental challenge in synthetic chemistry. Herein, we present an efficient carboxylation method via the photoredox-catalyzed cleavage of benzylic C(sp)-O bonds in ethers with carbon dioxide (CO). Diverse primary, secondary, and tertiary benzyl ethers undergo selective carboxylation with CO to generate valuable aryl acetic acids, including several drug molecules. This photocatalyzed carboxylation reaction is operationally simple to implement and versatile for various benzylic ethers, exhibiting favorable compatibility with diverse functional groups. Mechanistic studies indicate that the single electron transfer (SET) reduction of ethers might be the key to generating a highly reactive radical anion intermediate, which could undergo C-O bond cleavage and another SET reduction process to generate carbanions for reaction with CO.
尽管在特定底物的位点选择性C-O键官能化方面已取得显著进展，但醚类中C(sp)-O键的选择性裂解和官能化仍是合成化学中的一项基本挑战。在此，我们报道了一种通过光氧化还原催化醚类中苄基C(sp)-O键与二氧化碳（CO₂）裂解实现高效羧化的方法。多种伯、仲和叔苄基醚与CO₂发生选择性羧化反应，生成有价值的芳基乙酸，包括几种药物分子。这种光催化羧化反应操作简单，适用于各种苄基醚，对多种官能团具有良好的兼容性。机理研究表明，醚类的单电子转移（SET）还原可能是生成高活性自由基阴离子中间体的关键，该中间体可进行C-O键裂解和另一个SET还原过程，生成碳负离子以与CO₂反应。
