作者:Jean-Claude Schärer、Robert Etienne、Ulrich Burger
DOI:10.1002/hlca.19850680823
日期:1985.12.18
intercepted by aldehydes and converted to the title alkenes in a few straightforward steps. Protonation of 1,1-di(1-pyrrolyl)ethylene (10) is found to occur under kinetic control at the terminal olefinic position. In HBF4. Me2O the resulting 5-azionafulvene-type ion 14 can be observed by low-temperature NMR spectroscopy. In FSO3H, however, protonation is directed under thermodynamic control to both pyrrole
结果表明,取决于所选择的溶剂和络合剂,二(1-吡咯基)甲烷(3)的锂化可以直接指向C(α)环位置或指向中心CH 2基团。CH 2脱质子化反应生成的二(1-吡咯基)-甲基锂(6)被醛截留并在几个简单的步骤中转化为标题烯烃。发现在动力学控制下在末端烯烃位置发生1,1-二(1-吡咯基)乙烯(10)的质子化。在HBF 4中。对于Me 2 O,可以通过低温NMR光谱法观察到所生成的5-叠氮基富烯型离子14。在FSO 3中然而,H在热力学控制下被导向两个吡咯环。所得到的对称指示剂13即使在室温下也持续存在。