Tetrylenes Chelated by Hybrid Amido–Amino Ligand: Derivatives of 2-[(N,N-Dimethylamino)methyl]aniline

Reaction of 2-[(dimethylamino)methyl]aniline with butyllithium, followed by conversion with trimethylsilyl, triphenylsilyl, triphenylgermyl, trimethylstannyl, or tri-n-butylstannyl chloride, gives the corresponding substituted aniline. These compounds were further deprotonated by butyllithium and reacted with germanium, tin, and lead dichlorides, respectively, in both stoichiometric ratios 2:1 and 1:1, providing the target homo- ([2-(Me2NCH2)C6H4(YR3)N]2M) and heteroleptic ([2-(Me2NCH2)C6H4(YR3)N]MCl) germylenes and stannylenes, where M = Ge, Sn, Y = Si, Ge, and R = Me, Ph. Unlike all of these cases, the heteroleptic plumbylene can only be obtained with this reaction when the amide is substituted by a trimethylsilyl moiety. Anilines substituted by trimethyltin or tri-n-butyltin moieties gave transmetalation products after the second deprotonation by butyllithium. The trimethyltin-substituted stannylenes could likewise not be obtained by hexamethyldisilazane elimination of (trimethylstannyl)-2-[(dimethylamino)methyl]aniline with 0.5 mol equiv of either bis[bis(trimethylsilyl)amido]tin or {bis[bis(trimethylsilyl)amido]tin chloride}. Products of these reactions are heterocubanes with compositions {[2-(Me2NCH2)C6H4N]Sn}4 and [2-(Me2NCH2)C6H4N]2(μ2-SnMe2)2, respectively, and Me4Sn or Me3SnCl. The structures of trimethylsilyl- and triphenylgermyl-substituted germylenes, stannylenes, and plumbylenes, as well as a number of their precursors, in the crystalline state, were investigated by X-ray diffraction and NMR spectroscopy in solution. Density functional theory methods were used for evaluation of the structures of several compounds.

将2-[(二甲氨基)甲基]苯胺（2-[(dimethylamino)methyl]aniline）与丁基锂（butyllithium）反应，再分别与三甲基硅基氯（trimethylsilyl chloride）、三苯基硅基氯（triphenylsilyl chloride）、三苯基锗基氯（triphenylgermyl chloride）、三甲基锡基氯（trimethylstannyl chloride）或三正丁基锡基氯（tri-n-butylstannyl chloride）进行转化反应，可得到相应的取代苯胺。上述所得化合物可进一步经丁基锂去质子化，并分别以2:1与1:1的化学计量比与二氯化锗、二氯化锡、二氯化铅反应，合成目标同配型（homo-）与异配型（heteroleptic）锗烯类（germylenes）及锡烯类（stannylenes）化合物，其通式分别为[2-(Me₂NCH₂)C₆H₄(YR₃)N]₂M与[2-(Me₂NCH₂)C₆H₄(YR₃)N]MCl，其中M=Ge、Sn，Y=Si、Ge，R=Me、Ph。与上述所有反应体系不同，仅当酰胺被三甲基硅基（trimethylsilyl）取代时，该反应方可得到异配型铅烯类（plumbylenes）化合物。带有三甲基锡基或三正丁基锡基取代基的苯胺，经丁基锂第二次去质子化后会生成转金属化产物。通过六甲基二硅氮烷消除反应，以0.5摩尔当量的双[双(三甲基硅基)氨基]锡或{双[双(三甲基硅基)氨基]氯化锡}与(三甲基锡基)-2-[(二甲氨基)甲基]苯胺反应，同样无法得到三甲基锡基取代的锡烯类化合物。上述反应的产物分别为组成为{[2-(Me₂NCH₂)C₆H₄N]Sn}₄与[2-(Me₂NCH₂)C₆H₄N]₂(μ₂-SnMe₂)₂的杂立方烷（heterocubanes），以及Me₄Sn与Me₃SnCl。通过X射线衍射（X-ray diffraction）与溶液相核磁共振波谱（NMR spectroscopy）表征了三甲基硅基及三苯基锗基取代的锗烯类、锡烯类、铅烯类化合物，以及部分前驱体的单晶结构；采用密度泛函理论（density functional theory）方法对多种化合物的结构进行了评估。