Technische Universität Berlin, Department of Chemistry: Metalorganics and Inorganic Materials, Sekr. C2, Strasse des 17. Juni 135, 10623 Berlin, Germany.
Chem Asian J. 2012 Sep;7(9):2145-50. doi: 10.1002/asia.201200379. Epub 2012 Jun 14.
Modifying the β-diketimine ligand LH 1 (LH=[ArN=C(Me)-CH=C(Me)-NHAr], Ar=2,6-iPr(2)C(6)H(3)) through replacement of the proton in 3-position by a benzyl group (Bz) leads to the new (Bz)LH ligand 2, which could be isolated in 77% yield. According to (1) H NMR spectroscopy, 2 is a mixture of the bis(imino) form (ArN=C(Me)CH(Bz) 2a and its tautomer [ArN=C(Me)-C(Bz)=C(Me)NHAr] 2b. Nevertheless, lithiation of the mixture of 2a and 2b affords solely the N-lithiated β-diketiminate [ArN=C(Me)-C(Bz)=C(Me)-NLiAr], (Bz)LLi 3. The latter reacts readily with GeCl(2)· dioxane to form the chlorogermylene (Bz)LGeCl 4, which serves as a precursor for a new zwitterionic germylene by dehydrochlorination with LiN(SiMe(3))(2). This reaction leads to the zwitterionic germylene (Bz)L'Ge: 5 ((Bz)L'=ArNC(=CH(2))C(Bz)=C(Me)NAr) which could be isolated in 83% yield. The benzyl group has a distinct influence on the reactivity of zwitterionic 5 in comparison to its benzyl-free analogue, as shown by the reaction of 5 with phenylacetylene, which yields solely the 1,4-addition product 6, that is, the alkynyl germylene (Bz)LGeCCPh. Compounds 2-6 have been fully characterized by multinuclear NMR spectroscopy, mass spectrometry, elemental analyses, and single-crystal X-ray diffraction analyses.
通过用苄基（Bz）取代 3 位上的质子，将β-二酮亚胺配体 LH1（LH=[ArN=C(Me)-CH=C(Me)-NHAr]，Ar=2,6-iPr(2)C(6)H(3)）进行修饰，得到新的（Bz）LH 配体 2，其可以以 77%的产率分离出来。根据（1）H NMR 光谱，2 是双（亚氨基）形式(ArN=C(Me)CH(Bz)2a 和其互变异构体[ArN=C(Me)-C(Bz)=C(Me)NHAr]2b 的混合物。然而，混合物 2a 和 2b 的锂化仅得到 N-锂化的β-二酮亚胺[ArN=C(Me)-C(Bz)=C(Me)-NLiAr]，（Bz）LLi3。后者容易与 GeCl(2)·二氧六环反应，形成氯代锗亚基（Bz）LGeCl4，它通过与 LiN(SiMe(3))(2)脱氯化氢反应，作为一种新的两性锗亚基的前体。该反应导致两性锗亚基（Bz）L'Ge：5（（Bz）L'=ArNC(=CH(2))C(Bz)=C(Me)NAr）以 83%的产率分离出来。与无苄基的类似物相比，苄基对两性 5 的反应性有明显的影响，这可以通过 5 与苯乙炔的反应得到证明，该反应仅生成 1,4-加成产物 6，即炔基锗亚基（Bz）LGeCCPh。化合物 2-6 通过多核 NMR 光谱、质谱、元素分析和单晶 X 射线衍射分析进行了全面表征。
