Departamento de Química Orgánica, Facultad de Ciencias, and Instituto de Síntesis Orgánica, Universidad de Alicante, Apdo. 99, 03080-Alicante, Spain.
J Org Chem. 2009 Nov 6;74(21):8191-5. doi: 10.1021/jo901681s.
Activated and deactivated aryl and heteroaryl chlorides are efficiently cross-coupled with potassium vinyl- and alkenyltrifluoroborates using 4-hydroxyacetophenone oxime derived palladacycle as precatalyst in 1 to 3 mol % Pd loading, Binap as ligand, and Cs(2)CO(3) as base in DMF at 120 degrees C. The reactions can also be performed using Pd(OAc)(2) as Pd(0) source, although with lower efficiency. Bidentate ligands such as Binap and dppp can be used, the former being the best choice. Only in the case of deactivated aryl chlorides should the reaction temperature be increased to 160 degrees C to achieve good yields. The corresponding cross-coupled compounds, such as styrenes, stilbenes, and alkenylarenes, are obtained in good yields and with high regio- and diastereoselectivity.
用 4-羟基苯乙酮肟衍生的钯环配合物作为前催化剂,在 1 至 3 摩尔%的 Pd 负载量、BINAP 作为配体和 Cs2CO3 作为碱的条件下,在 DMF 中于 120°C 下,芳基和杂芳基氯可以有效地与钾乙烯基和烯基三氟硼酸盐交叉偶联。该反应也可以使用 Pd(OAc)2 作为 Pd(0)源进行,尽管效率较低。可以使用双齿配体,如 BINAP 和 dppp,前者是最佳选择。只有在活化的芳基氯的情况下,反应温度才需要升高至 160°C 以获得良好的产率。相应的交叉偶联化合物,如苯乙烯、二苯乙烯和烯基芳烃,以高产率和高区域和立体选择性获得。