Electrocyclic aromatic substitution by nitrile ylides to give 3H-2-benzazepines: substituent effects and mechanism
作者:Paul W. Groundwater、John T. Sharp
DOI:10.1016/s0040-4020(01)80469-5
日期:1992.1
substitution at the ortho (2′) position irrespective of their polar electronic effects. Deuterium labelling studies have shown that the cyclisation step is irreversible for these nitrile ylides in contrast to the analogous diazo-compounds (3) for which it is reversible.
由碱诱导的亚氨酰氯的脱氯化氢反应生成的苯甲腈3,3-二芳基烯丙基腈(16),通过1,7环闭合环化,得到3H-2-苯并ze庚因,例如(19),与类似的重氮化合物相反(1)优选1,5-电环化。不对称放置的取代基[(16b–e)中的R ]倾向于在邻位(2')处进行取代,无论其极性电子效应如何。氘标记研究表明,与类似的重氮化合物(3)相反,这些腈基的环化步骤是不可逆的。