Albuerne Isabel G, Alvarez M Angeles, García M Esther, García-Vivó Daniel, Ruiz Miguel A, Vega Patricia
Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo, E-33071 Oviedo, Spain.
Inorg Chem. 2020 Jun 1;59(11):7869-7883. doi: 10.1021/acs.inorgchem.0c00995. Epub 2020 May 21.
The reactivity of the complex [MoCp(μ-κ:κ,η-PCH)(CO)(η-HMes*)(PMe)] () toward different diazoalkanes and organic azides was investigated. The pyramidal phosphinidene ligand in displayed a strong nucleophilicity, enabling these reactions to proceed rapidly even below room temperature. Thus, reacted rapidly at 253 K with different diazoalkanes NCRR' (R,R' = H,H, Ph,Ph, H,COEt) to give the corresponding P:P-bridged phosphadiazadiene derivatives as major products which, however, could not be isolated. Reaction of the latter with H(OEt) yielded the corresponding cationic derivatives MoCp{μ-κ:κ,η-P(NHNCRR')CH}(η-HMes*)(CO)(PMe), which were isolated in ca. 70% yield. The related species MoCp{μ-κ:κ,η-P(NMeNCHCOEt)CH}(η-HMes*)(CO)(PMe) was isolated upon reaction of the ethyl diazoacetate derivative with MeI and subsequent anion exchange with Na(BAr'). Reaction of with aryl azides (4-CHMe)N and (4-CHF)N proceeded rapidly at low temperature to give possibly the corresponding P:P-bridged phosphaimine derivatives as major products, which could be neither isolated. Protonation of these products with H(OEt) gave the corresponding aminophosphanyl complexes MoCp{μ-κ:κ,η-P(NHR)CH}(η-HMes*)(CO)(PMe), isolated in ca. 75% yield. In contrast, the result of reactions of with benzyl azide was strongly dependent on temperature, including the temperature in the subsequent methylation step that gave isolable cationic derivatives. By a careful choice of experimental conditions, different complexes having methylated phosphatriazadiene ligands were isolated, such as MoCp{μ-κ:κ,η-P(NNNMeCHPh)CH}(η-HMes*)(CO)(PMe) and the metallacyclic derivatives - and -MoCp{μ-κ:κ,η-P(NMeNNCHPh)CH}(η-HMes*)(CO)(PMe). Density functional theory calculations, along with NMR monitoring experiments, revealed that the formation of the latter products stemmed from different and kinetically favored phosphatriazadiene intermediates, thermodynamically disfavored with respect to the denitrogenation process, otherwise yielding phosphaimine derivatives.
研究了配合物[MoCp(μ-κ:κ,η-PCH)(CO)(η-HMes*)(PMe)]（）与不同重氮烷和有机叠氮化物的反应活性。中呈金字塔形的磷烯配体表现出很强的亲核性，使得这些反应即使在室温以下也能快速进行。因此，在253 K下与不同的重氮烷NCRR'（R，R' = H，H，Ph，Ph，H，COEt）迅速反应，以相应的P:P桥连磷二氮二烯衍生物作为主要产物，但这些产物无法分离出来。后者与H(OEt)反应生成相应的阳离子衍生物MoCp{μ-κ:κ,η-P(NHNCRR')CH}(η-HMes*)(CO)(PMe)，分离产率约为70%。重氮乙酸乙酯衍生物与MeI反应，随后与Na(BAr')进行阴离子交换，分离得到相关物种MoCp{μ-κ:κ,η-P(NMeNCHCOEt)CH}(η-HMes*)(CO)(PMe)。与芳基叠氮化物(4-CHMe)N和(4-CHF)N在低温下迅速反应，可能以相应的P:P桥连磷亚胺衍生物作为主要产物，但这些产物也无法分离出来。用H(OEt)将这些产物质子化，得到相应的氨基膦基配合物MoCp{μ-κ:κ,η-P(NHR)CH}(η-HMes*)(CO)(PMe)，分离产率约为75%。相比之下，与苄基叠氮化物反应的结果强烈依赖于温度，包括后续甲基化步骤中能得到可分离阳离子衍生物的温度。通过仔细选择实验条件，分离得到了具有甲基化磷三氮二烯配体的不同配合物，如MoCp{μ-κ:κ,η-P(NNNMeCHPh)CH}(η-HMes*)(CO)(PMe)以及金属环衍生物 - 和 -MoCp{μ-κ:κ,η-P(NMeNNCHPh)CH}(η-HMes*)(CO)(PMe)。密度泛函理论计算以及NMR监测实验表明，后一种产物的形成源于不同的且动力学上有利的磷三氮二烯中间体，相对于脱氮过程在热力学上不利，否则会生成磷亚胺衍生物。
