Krämer Felix, Radius Michael, Hinz Alexander, Dilanas Melina E A, Breher Frank
Karlsruhe Institute of Technology (KIT), Institute of Inorganic Chemistry, Division Molecular Chemistry, Engesserstraße 15, 76131, Karlsruhe, Germany.
Chemistry. 2022 Jan 3;28(1):e202103974. doi: 10.1002/chem.202103974. Epub 2021 Dec 9.
The synthesis and full characterization of α-silylated (α-SiCPs; 1-7) and α-germylated (α-GeCPs; 11-13) phosphorus ylides bearing one chloride substituent R PC(R )E(Cl)R (R=Ph; R =Me, Et, Ph; R =Me, Et, iPr, Mes; E=Si, Ge) is presented. The molecular structures were determined by X-ray diffraction studies. The title compounds were applied in halide abstraction studies in order to access cationic species. The reaction of Ph PC(Me)Si(Cl)Me (1) with Na[B(C F ) ] furnished the dimeric phosphonium-like dication [Ph PC(Me)SiMe ] [B(C F ) ] (8). The highly reactive, mesityl- or iPr-substituted cationic species [Ph PC(Me)SiMes ][B(C F ) ] (9) and [Ph PC(Et)SiiPr ][B(C F ) ] (10) could be characterized by NMR spectroscopy. Carrying out the halide abstraction reaction in the sterically demanding ether iPr O afforded the protonated α-SiCP [Ph PCH(Et)Si(Cl)iPr ][B(C F ) ] (6 dec) by sodium-mediated basic ether decomposition, whereas successfully synthesized [Ph PC(Et)SiiPr ][B(C F ) ] (10) readily cleaves the F-C bond in fluorobenzene. Thus, the ambiphilic character of α-SiCPs is clearly demonstrated. The less reactive germanium analogue [Ph PC(Me)GeMes ][B{3,5-(CF ) C H } ] (14) was obtained by treating 11 with Na[B{3,5-(CF ) C H } ] and fully characterized including by X-ray diffraction analysis. Structural parameters indicate a strong C -Ge interaction with high double bond character, and consequently the C-E (E=Si, Ge) bonds in 9, 10 and 14 were analyzed with NBO and AIM methods.
本文介绍了带有一个氯取代基(R_2PC(R^1)E(Cl)R^2)（(R = Ph)；(R^1 = Me)、(Et)、(Ph)；(R^2 = Me)、(Et)、(iPr)、(Mes)；(E = Si)、(Ge)）的α-硅基化磷叶立德（α-SiCPs；1 - 7）和α-锗基化磷叶立德（α-GeCPs；11 - 13）的合成及全面表征。通过X射线衍射研究确定了分子结构。将标题化合物应用于卤化物提取研究以获得阳离子物种。(Ph_2PC(Me)Si(Cl)Me)（1）与(Na[B(C_6F_5)_4])反应生成二聚鏻状双阳离子([Ph_2PC(Me)SiMe_2][B(C_6F_5)_4])（8）。高反应性的、均三甲苯基或异丙基取代的阳离子物种([Ph_2PC(Me)SiMes_2][B(C_6F_5)_4])（9）和([Ph_2PC(Et)SiiPr_2][B(C_6F_5)_4])（10）可用核磁共振光谱进行表征。在空间位阻较大的醚(iPr_2O)中进行卤化物提取反应，通过钠介导的碱性醚分解得到质子化的α-SiCP([Ph_2PCH(Et)Si(Cl)iPr_2][B(C_6F_5)_4])（6 dec），而成功合成的([Ph_2PC(Et)SiiPr_2][B(C_6F_5)_4])（10）能轻易裂解氟苯中的(F - C)键。因此，清楚地证明了α-SiCPs的双亲性。通过用(Na[B{3,5-(CF_3)_2C_6H_3}_4])处理11得到反应性较低的锗类似物([Ph_2PC(Me)GeMes_2][B{3,5-(CF_3)_2C_6H_3}_4])（14），并通过X射线衍射分析等方法进行了全面表征。结构参数表明存在具有高双键特征的强(C - Ge)相互作用，因此用自然键轨道（NBO）和分子中的原子（AIM）方法对9、10和14中的(C - E)（(E = Si)、(Ge)）键进行了分析。
