Ionic liquids accelerating cycloaddition between 1-aryl-2-halocyclopropenes and furan
作者:May-Fan Ding、Shaw-Tao Lin、Woan-Ju Chang
DOI:10.3998/ark.5550190.0011.219
日期:——
with furan in a RTIL to give a fair good yield of the [4+2]-cycloadducts with more than 90% of the exo-isomer. The imidazolium type ionic liquids are able to accelerate this cycloaddition process with high steric selectivity. Neither pyrrole nor thiophene undergoes the cycloaddition with cyclopropene to form the [4+2]-cycloadduct. 1-Aryl-3,3-difluoro-2-halocyclopropenes are inert towards furan even
在 -10 oC 下用 t-BuOK 处理一系列 1-芳基-2,2-二卤代环丙烷得到相应的 1-芳基-2卤代环丙烯,它与呋喃在 RTIL 中反应得到相当好的 [4+2 ]-环加合物具有超过 90% 的外型异构体。咪唑鎓型离子液体能够以高空间选择性加速这种环加成过程。吡咯和噻吩都不会与环丙烯发生环加成反应形成 [4+2]-环加合物。即使在高于 100 oC 的温度下,1-Aryl-3,3-difluoro-2-halocyclopropenes 对呋喃也是惰性的。