Pericyclic reactions of cyclopentadienones with nonactivated olefins in phenolic solvents. Enhancement of the reactivity and periselectivity
作者:Tamaki Jikyo、Masashi Eto、Kazunobu Harano
DOI:10.1016/s0040-4020(99)00259-8
日期:1999.5
pericyclic reactions of cyclopentadienones with olefins involving conjugated medium-ring polyenes has been investigated. The use of phenols as a solvent accelerates the reaction rates of cycloadditions of cyclopentadienones with nonactivated olefins. In the reaction of cycloheptatriene in p-chlorophenol, the exo [4+6]π cycloadduct was produced predominantly, in which a 15-fold increase of the reaction rate
研究了酚对环戊二烯酮与涉及共轭中环多烯的烯烃的周环反应的反应性和选择性的影响。酚作为溶剂的使用加速了环戊二烯酮与非活化烯烃的环加成反应的速率。在环庚三烯在对氯苯酚中的反应中,主要生成外[4 + 6] π环加合物,与苯相比,反应速率提高了15倍。苯酚还促进了初级环加合物的[3,3]-亲和性和脱羰基作用。在动力学和分子轨道(MO)计算数据的基础上,讨论了酚类的可能作用。