催化学报 ›› 2022, Vol. 43 ›› Issue (7): 1667-1673.DOI: 10.1016/S1872-2067(21)63859-7

• 二氧化碳催化转化专栏 • 上一篇    下一篇

可见光催化二氧化碳与苄位卤代物的羧基化: 温和条件且无过渡金属

敬科a, 魏明恺a, 颜思顺a, 廖黎丽a, 牛亚楠a, 罗书平b, 于博a,*(), 余达刚a,#()   

  1. a四川大学化学学院, 绿色化学与技术教育部重点实验室, 四川成都610064
    b浙江工业大学, 绿色化学合成技术国家重点实验室(筹), 浙江杭州310014
  • 收稿日期:2021-04-13 接受日期:2021-05-22 出版日期:2022-05-20 发布日期:2021-06-15
  • 通讯作者: 于博,余达刚
  • 基金资助:
    国家自然科学基金(21822108);国家自然科学基金(21772129);中国博士后面上基金(2020M683301);四川省青年科技创新研究团队项目(20CXTD0112)

Visible-light photoredox-catalyzed carboxylation of benzyl halides with CO2: Mild and transition-metal-free

Ke Jinga, Ming-Kai Weia, Si-Shun Yana, Li-Li Liaoa, Ya-Nan Niua, Shu-Ping Luob, Bo Yua,*(), Da-Gang Yua,#()   

  1. aKey Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, Sichuan, China
    bState Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
  • Received:2021-04-13 Accepted:2021-05-22 Online:2022-05-20 Published:2021-06-15
  • Contact: Bo Yu, Da-Gang Yu
  • About author:Da-Gang Yu (College of Chemistry, Sichuan University) was invited as a young member of the 6th Editorial Board of Chin. J Catal. in 2020. Prof. Da-Gang Yu received his B.S. degree from Sichuan University (P. R. China) in 2007 and Ph.D. degree with Prof. Zhang-Jie Shi from Peking University (P. R. China), 2012. He carried out postdoctoral research with Humboldt fellowship in the group of Prof. Frank Glorius, Muenster University (Germany). Since 2015, he has been working independently in Sichuan University (China) with support from “The Thousand Young Talents Plan” and the National Natural Science Foundation of China‒Outstanding Young Scholars. His research interests mainly focus on novel transformations of CO2, radical chemistry and novel transition-metal catalysis. He has coauthored about 90 peer-reviewed papers and 11 patents.
  • Supported by:
    National Natural Science Foundation of China(21822108);National Natural Science Foundation of China(21772129);China Postdoctoral Science Foundation(2020M683301);Sichuan Science and Technology Program(20CXTD0112)

摘要:

二氧化碳(CO2)作为一种无毒、廉价、可再生的碳一合成子, 被广泛用于合成重要的精细化学品. 芳基乙酸广泛存在于许多药物分子中, 是一类重要的羧酸分子. 苄位卤代物具有商业可得且价格低廉的优势, 是合成芳基乙酸的理想底物. 因此, 以苄位卤代物和CO2为原料合成芳基乙酸具有很大的吸引力. 传统的合成方法需要将苄基卤化物预先制备成水、氧敏感的苄位金属试剂, 再与CO2发生羧基化反应, 但因兼容性较差, 操作繁琐, 限制了实际应用. 另外, 苄位卤化物与CO2的直接电羧基化反应也有报道, 但存在需要牺牲阳极、使用贵金属电极和支持电解质等不足. 此外, 过渡金属催化苄位卤代物与CO2羧基化反应得到长足发展, 但也存在底物范围有限、官能团兼容性不佳、使用金属还原剂和存在重金属污染等问题.

近年来, 可见光催化已经成为实现CO2高效转化的有力工具, 具有绿色环保、官能团兼容性好等特点. 如果能利用可见光催化实现苄位卤代物与CO2的还原羧基化, 将可以进一步提升该类转化的底物适用性和反应的实用性. 本文利用廉价的有机染料为光敏剂和有机胺为电子给体, 在常压CO2和室温条件下, 实现了苄位氯代物和溴代物的还原羧基化反应. 一级、二级和三级的苄位卤代物都能顺利地参与该羧基化反应, 芳环上的卤原子和硼酸酯等常见的偶联官能团也能兼容. 另外, 成功地将这种方法放大到了克级反应, 合成了一些重要的药物分子和药物分子前体, 实现了一些重要的天然产物的羧酸化衍生, 证明了这种合成方法具有潜在的应用价值. 机理实验结果表明, 该反应很可能主要经历还原态的光敏剂对苄位卤代物的两次单电子还原过程, 从而先后产生苄位自由基和苄位碳负离子, 后者可以快速捕获CO2生成羧酸盐, 质子化后生成芳基乙酸. 综上, 可见光催化的羧基化反应具有反应条件温和、无需过渡金属参与、底物范围广、官能团兼容性好、易克级放大、催化剂用量低等优势, 为实现芳基乙酸的高效合成提供了一种新方法.

关键词: 二氧化碳, 可见光催化, 羧基化, 芳基乙酸, 苄位卤代物

Abstract:

The visible-light photoredox-catalyzed carboxylation of benzyl chlorides and bromides with CO2 has been reported. With inexpensive organic dyes as photocatalysts and amines as electron donors, this carboxylation proceeds well in the absence of sensitive organometallic reagents, transition metal catalysts, or metallic reductants. A wide range of commercially available and inexpensive benzyl halides undergo such carboxylation to give valuable aryl acetic acids, including several pharmaceutical molecules and drug precursors, in moderate to high yields. Moreover, this reaction features mild reaction conditions (one atmospheric pressure of CO2 and room temperature), broad substrate scope, good functional group tolerance, easy scalability, and low catalyst loading, thus providing an efficient approach for the assembly of aryl acetic acids.

Key words: Carbon dioxide, Visible-light photoredox catalysis, Carboxylation, Aryl acetic acids, Benzyl halides