BF3⋅OEt2-Catalyzed Intermolecular Reactions of Vinylidenecyclopropanes with Bis(p-alkoxyphenyl)methanols: A Novel Cationic 1,4-Aryl-Migration Process
作者:Lei Wu、Min Shi、Yuxue Li
DOI:10.1002/chem.200903131
日期:——
BF3⋅OEt2‐catalyzed reactions of vinylidenecyclopropanes (VDCPs) 1 with bis(aryl)methanols 2 were thoroughly investigated. When VDCPs 1 reacted with electron‐rich bis(aryl)methanols 2, diastereomeric rotamers of indene derivatives formed in excellent yields by a novel cationic 1,4‐aryl migration between two carbon atoms and the subsequent intramolecular Friedel–Crafts reaction pathways in the presence
BF 3 ⋅OEt 2层的vinylidenecyclopropanes(VDCPs) -催化的反应1与双(芳基)基甲醇2进行了彻底调查。当VDCPs 1与富电子的双(芳基)甲醇2反应时,茚衍生物的非对映异构体以优异的收率形成,这是由于存在两个碳原子之间的新型阳离子1,4-芳基迁移以及随后的分子内Friedel-Crafts反应路径的BF 3 ⋅OEt 2温和的条件下。至于缺电子或少电子的双(芳基)甲醇2要么通过直接去质子化以高收率形成三烯产物,要么通过直接分子内Friedel-Crafts反应产生另一种类型的茚衍生物,这取决于VDCPs的环丙烷上的取代基。另外,进行了DFT计算以解释实验结果。根据实验和计算结果,提出了所有这些转换的合理机制。