formation. Then a singlet biradical intermediate is formed. In the biradical, an α hydrogen atom of the tropothione moiety is moved to the benzyne moiety. A closed-shell intermediate is generated. This allene-type intermediate is isomerized to the second intermediate. The intramolecular proton shift in the latter leads to the three products. The biradical character of the benzyne has a key role in the present
通过实验和计算研究了苯并-对
硫磷的反应。通过使用两个苯炔源的仔细实验,检测到三个异构体产物。确定了三种等摩尔产物。未检测到预期的对称性允许的[4 + 2]或[8 + 2]环加合物。为了解释意外的结果,进行了密度泛函计算和完整的活动空间自洽场(CASSCF)计算。首先,通过单中心CS键形成将苯并炔添加至对
硫磷。然后形成单重双自由基中间体。在双自由基中,对
硫磷根部分的α氢原子移动到苯并炔部分。生成了一个闭壳中间体。该
丙二烯型中间体异构化为第二中间体。后者的分子内质子转移产生了三种产物。苯并的双自由基特性在本反应中起关键作用,并已参考其他苯并反应进行了讨论。