Syntheses of Tetrasubstituted [10]Cycloparaphenylenes by a Pd‐catalyzed Coupling Reaction. Remarkable Effect of Strain on the Oxidative Addition and Reductive Elimination
作者:Eiichi Kayahara、Masaya Nakano、Liansheng Sun、Kosuke Ishida、Shigeru Yamago
DOI:10.1002/asia.202000711
日期:2020.8.17
A small library of tetrasubstituted [10]cycloparaphenylene ([10]CPP) derivatives bearing alkyl, alkenyl, alkynyl and aryl substituents was constructed by a Pd‐catalyzed cross‐coupling reaction starting from tetratriflate [10]CPP 5 e, which was readily available in high yields on a >2 g scale. The CPP skeleton increases the reactivity of aryl triflate for oxidative addition to the Pd species, and 5 e
四取代的[10]环的一小库([10] CPP)衍生物轴承烷基,烯基,炔基和芳基取代基是通过从tetratriflate [10] CPP开始Pd-催化的交叉偶联反应构建5 ë,这是容易获得的> 2 g规模的高产量。该CPP骨架增加芳基三氟甲磺酸酯的反应性的氧化除钯物种,和5 ë是10倍比其线性对苯类似物更具反应性的,如通过竞争实验来确定。理论计算表明,未参与反应的每个对亚苯基单元产生的小的应变释放的累积是观察到的增强的反应性的原因。