Mechanochemistry of Cubane
Mechanochemistry of Cubane
复制标题
古巴烷的机械化学
DOI：
10.1021/jacs.2c10878
复制
发表时间：
2022
影响因子：
15
通讯作者：
Craig, Stephen L.
中科院分区：
文献类型：
--
作者：
Wang, Liqi;Zheng, Xujun;Kouznetsova, Tatiana B.;Yen, Tiffany;Ouchi, Tetsu;Brown, Cameron L.;Craig, Stephen L.
我们报道了高张力五环烃立方烷的机械化学反应性。探讨了立方烷的机械反应性与1，2-，1，3-和1，4-取代的拉附件的三个区域异构体。而所有的化合物都可以热活化，机械活化，观察到通过脉冲超声处理的含立方烷的聚合物，只有当力是通过1，2-附件。力偶联反应的单一观察到的产物是一个热inaccessibyn-tricycloococcus，与环辛四烯（热观察）或一对环丁二烯，将导致从顺序环丁烷断裂。通过单分子力谱法进一步定量了立方烷的机械化学反应性，力耦合开环速率常数在1.55 nN的力下达到1.33 s-1，低于传统环丁烷的典型力1.8-2.0 nN。
We report the mechanochemical reactivity of the highly strained pentacyclic hydrocarbon cubane. The mechanical reactivity of cubane is explored for three regioisomers with 1,2-, 1,3-, and 1,4-substituted pulling attachments. Whereas all compounds can be activated thermally, mechanical activation is observed via pulsed ultrasonication of cubane-containing polymers only when force is applied via 1,2-attachment. The single observed product of the force-coupled reaction is a thermally inaccessiblesyn-tricyclooctadiene, in contrast to cyclooctatetraene (observed thermally) or a pair of cyclobutadienes that would result from sequential cyclobutane scission. We further quantify the mechanochemical reactivity of cubane by single molecule force spectroscopy, and force-coupled rate constants for ring opening reach ∼33 s–1at a force of ∼1.55 nN, lower than forces of 1.8–2.0 nN that are typical of conventional cyclobutanes.