C−I Selective Sonogashira and Heck Coupling Reactions Catalyzed by Aromatic Triangular Tri‐palladium
C−I Selective Sonogashira and Heck Coupling Reactions Catalyzed by Aromatic Triangular Tri‐palladium
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芳香族三角三钯催化的 CâI 选择性 Sonogashira 和 Heck 偶联反应
DOI：
10.1002/ejoc.202200009
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发表时间：
2022
影响因子：
2.8
通讯作者：
Lingang Wu
中科院分区：
文献类型：
--
作者：
Xiaoshuang Wang;Lei Sun;Miaomiao Wang;Giovanni Maestri;Max Malacria;Xiang Liu;Yanlan Wang;Lingang Wu
芳香族三角形三钯阳离子1 -3，简称[Pd 3]+，具有有趣的光电性质、刘易斯碱性和优异的催化加氢活性。在此，我们报告了这些三钯配合物催化的高效和C−I选择性Sonogashira和Heck偶联反应。得益于适中的C-I键缔合能，这些三钯化合物在偶联反应中对芳基碘的反应性优于溴代芳烃。在Sonogashira途径中，实现了良好至优异的分离产率（71- 95%）。革兰氏规模反应达到93%的产率，钯负载量低至0.06摩尔%。 我们还探讨了苯基炔和芳基碘，包括杂芳族化合物，如噻吩，吡啶，吡唑和吡嗪的电子和空间效应。类似地，通过芳基碘和烯烃的催化Heck偶联，对于1.5mol%的钯负载量获得71- 96%的产率。 HRMS监测显示，[Pd 3]+由于其稳健性而在催化过程中保持为整体实体。
Aromatic triangular tri‐palladium cations1–3, abbreviated as [Pd3]+, have shown interesting photoelectric properties, Lewis basic character, and excellent activities in catalytic hydrogenation. Herein, we report the highly efficient and C−I selective Sonogashira and Heck coupling reactions catalyzed by these tri‐palladium complexes. Benefiting from the moderate C−I bond association energy, these tri‐palladiums presented exclusive reactivities to aryl iodides over the brominated aromatics in coupling reactions. In the Sonogashira pathway, good to excellent isolated yields (71–95 %) were achieved. Gram‐scale reaction reached 93 % of yield with palladium loading as few as 0.06 mol %. We also explored the electronic and steric effects for phenyl alkynes and aryl iodides including heteroaromatics like thiophene, pyridine, pyrazole, and pyrazine. Similarly, yields of 71–96 % were obtained for palladium loading of 1.5 mol% through catalyzed Heck coupling of aryl iodides and alkenes. The HRMS monitoring revealed that [Pd3]+maintained as whole entity during the catalytic process due to its robusness.