A Surprisingly Stable 1‐(Chlorosilyl)‐2‐phosphaethenyllithium Compound, RCl
<sub>2</sub>
SiC(Li)=PMes*
作者:Gabriela Cretiu Nemes、Henri Ranaivonjatovo、Jean Escudié、Ioan Silaghi‐Dumitrescu、Luminita Silaghi‐Dumitrescu、Heinz Gornitzka
DOI:10.1002/ejic.200400595
日期:2005.3
RCl2Si–C(Cl)=PMes* by lithium/chlorine exchange with nBuLi and evidence for its identity was obtained by hydrolysis. Remarkably, however, it failed to undergo a lithium salt elimination to form the corresponding chlorophosphasilaallene, RClSi=C=PMes*, even under prolonged heating in toluene. As shown by theoretical studies (RHF/3-21G* and RHF/6-31G**//RHF/3-21G* level), interactions between the lithium ion and the
RCl2Si–C(Li)=PMes* (1)(R = 9-甲基芴-9-基,Mes* = 2,4,6-三叔丁基苯基),被认为是合成杂烯的关键中间体RClSi=C=PMes*,通过与 nBuLi 的锂/氯交换从 RCl2Si–C(Cl)=PMes* 获得,并通过水解获得其身份的证据。然而,值得注意的是,即使在甲苯中长时间加热,它也未能进行锂盐消除以形成相应的氯代磷杂四烯丙二烯,RClSi=C=PMes*。理论研究表明(RHF/3-21G* 和 RHF/6-31G**//RHF/3-21G* 能级),锂离子与磷和硅原子上取代基的 π 系统之间的相互作用可以部分解释这种稳定性。锂化合物 1 与甲醇或氯三甲基硅烷反应生成新的甲硅烷基磷烯烃。锂衍生物 1 与苯甲醛的反应产生了一个四元杂环,带有一个环外 P=C 键,它实际上对应于 Si=C 和 C=O 双键之间 [2+2] 环加成的产物。(© Wiley-VCH