Probing Mechanisms of Aryl–Aryl Bond Cleavages under Flash Vacuum Pyrolysis Conditions
作者:Edward A. Jackson、Xiang Xue、Hee Yeon Cho、Lawrence T. Scott
DOI:10.1071/ch14171
日期:——
radicals; (2) hydrogen atom attachment to an ipso-carbon atom of the biaryl followed by C–C bond cleavage; (3) direct homolysis; and (4) loss of a fragment as an aryne. None of these mechanisms by itself successfully accommodates all of the experimental facts. The data suggest that aryl–aryl bond cleavages under FVP conditions involve at least two different mechanistic pathways and that the relative
几种联芳基已在1100°C和0.8-0.9 hPa的条件下进行了快速真空热解(FVP)。报告了9-苯基蒽(1),2-溴代联苯(5),联苯(8),1,10-二苯基蒽(12),9-(2-萘基)蒽(17)和9的FVP产品组成,9'-双蒽基(20)。实验结果已用于评估在这些条件下芳基-芳基键断裂的四种可能的机理途径:(1)取代苯基的“爆炸”;(2)氢原子与ipso的连接-联芳基的碳原子,然后进行CC键断裂;(3)直接匀浆;(4)丢失作为芳烃的片段。这些机制本身都不能成功地适应所有实验事实。数据表明,FVP条件下的芳基-芳基键裂解涉及至少两个不同的机理途径,竞争途径的相对贡献可能从一个联芳基变化到另一个。