Room-Temperature, Ligand- and Base-Free Heck Reactions of Aryl Diazonium Salts at Low Palladium Loading: Sustainable Preparation of Substituted Stilbene Derivatives
作者:François-Xavier Felpin、Karinne Miqueu、Jean-Marc Sotiropoulos、Eric Fouquet、Oier Ibarguren、Julia Laudien
DOI:10.1002/chem.200903050
日期:——
excellent stereoselectivity. The environmentally friendly protocol developed in this work features low palladium loading in technical‐grade methanol at room temperature under base‐, additive‐, and ligand‐free conditions. The same protocol applied to simple Heck coupling of aryl diazonium salts with methyl acrylate allows astonishingly low palladium loading, down to 0.005 mol %. The stereoselectivity experimentally
芳基重氮盐与2-芳基丙烯酸酯的Pd(OAc)2催化的Heck反应导致顺式-苯乙烯基苯甲酸酯具有良好的至优异的立体选择性。这项工作开发的环保协议的特点是,在室温下,在无碱,无添加剂和无配体的条件下,钯在工业级甲醇中的负载量较低。应用于芳基重氮盐与丙烯酸甲酯的简单Heck偶联的相同方案可实现低至0.005 mol%的低钯负载量。通过DFT计算合理化了实验观察到的合成顺式-苯乙烯衍生物的立体选择性。此外,通过计算研究已经清楚了甲醇在促进反应中的作用。