聊城大学黄现强团队报道了基于环仲胺N-氧化物单元的N，O-双齿配体钯配合物的合成及其在Mizoroki-Heck反应中的催化应用。相关研究成果发表在2023年12月9日出版的《中国化学》。

钯催化的Mizoroki-Heck反应是构建C_sp2-C_sp2键的一种强大而有效的方法。

该文简单合成了四种基于环状仲胺N-氧化物单元的N，O-双齿配体（L¹-L⁴）钯配合物（I-IV），并成功应用于芳基溴化物与缺电子烯烃的Mizoroki-Heck反应。X射线衍射分析表明，II的钯（II）原子呈畸变的正方形平面几何结构，并与来自两个配体（L²）的氮和氧原子四配位。在配合物II中，存在两个游离氯离子作为反阴离子。但IV的钯（II）中心由一个配体（L⁴）的氮和氧原子以及两个氯原子配位，呈现出近似正方形的平面几何结构。

钯配合物的催化性能研究表明，配合物II的催化活性高于其它配合物。一系列芳基溴化物和烯烃衍生物的偶联反应在2～5mol%钯络合物II的存在下进行，以良好至优异的产率得到所需的产物。

该方法具有官能团相容性好、产率高、反应时间短等优点，对构建功能分子和材料合成中的C_sp2-C_sp2键更具吸引力。

附：英文原文

Title: Palladium Complexes with N,O-bidentate Ligands Based on N-Oxide Units from Cyclic Secondary Amines:Synthesis and Catalytic Application in Mizoroki-Heck Reaction

Author: Xuefeng Jia, Yanyan Wen, Changhui He, Xianqiang Huang

Issue&Volume: 2023-12-09

Abstract: Palladium-catalyzed Mizoroki-Heck reaction is a powerful and efficient method for construction of Csp2-Csp2 bonds. Herein, four palladium complexes (I-IV) with N,O-bidentate ligands (L1-L4) based on N-oxide units from cyclic secondary amines were easily synthesized and successfully applied in Mizoroki-Heck reaction of aryl bromides with electron-deficient olefins. X-ray diffraction analyses indicated the palladium(II) atom of II took the distorted square planar geometry and was four-coordinated by nitrogen and oxygen atoms from two ligands (L2). Two free chloride ions were presented as counter anions in complex II. But the palladium(II) center of IV was coordinated by nitrogen and oxygen atoms from one ligands (L4) as well as two chlorine atoms, which exhibited the nearly square-planar geometry. The study on catalytic properties of palladium complexes revealed that complex II exhibited high activity superior to the other complexes. The coupling reactions of a series of aryl bromides and olefin derivatives proceeded in the presence of 2~5 mol% palladium complex II, giving to the desired products in good to excellent yields. The advantages of this method such as good compatibility of functional groups, high yields, and short reaction times made it more attractive for constructing Csp2-Csp2 bonds in synthesis of functional molecules and materials.

DOI: 10.1002/cjoc.202300375

Source: https://onlinelibrary.wiley.com/doi/10.1002/cjoc.202300375