Studies on the Intermolecular Hydroarylation of N-Ts- or N-Ac-Protected Indoles and 2,3-Allenoates
作者:Zhao Fang、Chunling Fu、Shengming Ma
DOI:10.1002/ejoc.201001661
日期:2011.3
An operationally simple, TFA-promoted regioselective hydroarylation reaction of 2,3-allenoates with N-Ts- or N-Ac-indoles to afford 4-indolyl-4-arylbut-2-enoates is described. A series of substrates was tested, and the E/Z selectivity was found to depend on the reaction temperature and time. A mechanism involving the formation of E and Z allylic carbocations generated in situ from the reaction of 2
描述了 2,3-alenoates 与 N-Ts-或 N-Ac-indoles 的操作简单、TFA 促进的区域选择性加氢芳基化反应,以提供 4-indoyl-4-arylbut-2-enoates。测试了一系列底物,发现 E/Z 选择性取决于反应温度和时间。提出了一种机制,该机制涉及由 2,3-烯丙酸与 TFA 反应原位生成的 E 和 Z 烯丙基碳正离子以及随后在吲哚的 3 位进行 Friedel-Crafts 攻击来解释结果。