Majeed Maitham H, Shayesteh Payam, Wallenberg L Reine, Persson Axel R, Johansson Niclas, Ye Lei, Schnadt Joachim, Wendt Ola F
Centre for Analysis snd Synthesis, Department of Chemistry, Lund University, Box 124, 221 00, Lund, Sweden.
Division of Synchrotron Radiation Research, Department of Physics, Lund University, Box 118, 221 00, Lund, Sweden.
Chemistry. 2017 Jun 22;23(35):8457-8465. doi: 10.1002/chem.201700777. Epub 2017 May 31.
Heterogeneous catalysts for selective oxidation of C-H bonds were synthesized by co-polymerization of new N-heterocyclic carbene-palladium(II) (NHC-Pd ) monomers with divinylbenzene. The polymer-supported NHC-Pd -catalysed undirected C-H acetoxylation of simple and methylated arenes as well as polyarenes, with similar or superior efficiency compared to their homogeneous analogues. In particular, the regioselectivity has been improved in the acetoxylation of biphenyl and naphthalene compared to the best homogeneous catalysts. The new polymer-supported catalysts maintain the original oxidation state of Pd after repeated catalytic reactions, and exhibit no significant leaching of palladium. In addition, the new catalysts have been successfully recovered and reused without loss of activity over several cycles of reactions.
通过新型N-杂环卡宾-钯（II）（NHC-Pd）单体与二乙烯基苯的共聚反应合成了用于C-H键选择性氧化的多相催化剂。聚合物负载的NHC-Pd催化简单芳烃、甲基化芳烃以及多芳烃的无定向C-H乙酰氧基化反应，与相应的均相类似物相比，具有相似或更高的效率。特别是，与最佳的均相催化剂相比，联苯和萘的乙酰氧基化反应的区域选择性得到了提高。新型聚合物负载催化剂在重复催化反应后保持Pd的原始氧化态，且钯没有明显的浸出。此外，新催化剂已成功回收并重复使用，在几个反应循环中均无活性损失。
