Stereochemical effects on the mechanochemical scission of furan–maleimide Diels–Alder adducts
Stereochemical effects on the mechanochemical scission of furan–maleimide Diels–Alder adducts
复制标题
呋喃-马来酰亚胺 Diels-Alder 加合物机械化学断裂的立体化学效应
DOI：
10.1039/c9cc06361g
复制
发表时间：
2019
影响因子：
4.9
通讯作者：
Craig, Stephen L.
中科院分区：
文献类型：
--
作者：
Wang, Zi;Craig, Stephen L.
阐明机械载体的化学结构与其机械反应性之间的相关性有助于机械化学系统的设计。一个最近受到广泛关注的特殊相关性是立体异构性和机械反应性之间的相关性。在这里，我们报告以前未观察到的差异，呋喃-马来酰亚胺狄尔斯-阿尔德（DA）立体异构体的机械反应性。我们评估了聚合物溶液的脉冲超声处理中机械触发的逆DA反应和偕二氯环丙烷机械基团的机械化学开环之间的内部竞争。在相同的聚合物中的两个sonomechanochemical反应的相对程度表明，内DA异构体表现出更大的机械不稳定性比其外异构体。这一结果与最近在类似系统中的相对断裂率的测量结果形成对比，并指出通过使用内部竞争获得的潜在增强的灵敏度，而不是在超声处理研究中评估机械反应性的绝对速率。
Clarifying the correlation between the chemical structure of mechanophores and their mechanical reactivity informs the design of mechanochemical systems. One specific correlation that has received much recent attention is that between stereoisomerism and mechanical reactivity. Here, we report previously unobserved differences in the mechanical reactivity of furan–maleimide Diels–Alder (DA) stereoisomers. We evaluated the internal competition between the mechanically triggered retro-DA reaction and the mechanochemical ring opening of gem-dichlorocyclopropane mechanophores in the pulsed sonication of polymer solutions. The relative extent of the two sonomechanochemical reactions in the same polymer shows that the endo DA isomer exhibits greater mechanical lability than its exo isomer. This result contrasts with recent measurements of the relative rates of scission in a similar system and points to potential enhanced sensitivity obtained through the use of internal competition as opposed to absolute rates in assessing mechanical reactivity in sonication studies.