Insertion Reaction of a Silylene into a N−H Bond of Hydrazine and a [1+4] Cycloaddition with Diphenyl Hydrazone

The reaction of a stable six-membered N-heterocyclic silylene, LSi (1) [L = CH{(CCH2)(CMe)(2,6-iPr2C6H3N)2}], with hydrazine and its derivatives is described. 1 reacts with hydrazine to form LSi(H)NHNH2 (2) under N−H bond insertion of the silylene. The reaction of 1 and N-methyl hydrazine results exclusively in the formation of LSi(H)NHNHMe (3). Treatment of 1 with an equimolar amount of diphenyl hydrazone in toluene yields the dearomatized siloxy-indolin-1-amine 4 in almost quantitative yield rather than the insertion product at the N−H bond of the NH2 group. Compounds 2−4 were characterized by microanalysis, multinuclear NMR, and IR spectroscopy. Compounds 2 and 4 are confirmed by X-ray structural analysis with the result that 2 and 4 are both monomeric and the silicon center of each resides in a distorted tetrahedral environment.

本文报道了稳定六元氮杂环硅烯（six-membered N-heterocyclic silylene）LSi（1）[配体L = CH{(C=CH₂)(CMe)(2,6-二异丙基苯氨基)₂}]与肼及其衍生物的反应。1与肼发生硅烯的N-H键插入反应，生成LSi(H)NHNH₂（2）。1与N-甲基肼反应仅专一生成LSi(H)NHNHMe（3）。将1与等摩尔量的二苯腙在甲苯中反应，以近乎定量的收率得到脱芳构化硅氧基吲哚啉-1-胺（4），而非NH₂基团N-H键的插入产物。通过元素分析、多核核磁共振波谱（multinuclear NMR）及红外光谱（IR spectroscopy）对化合物2~4进行了表征。经X射线结构分析（X-ray structural analysis）确认，化合物2和4均为单体结构，二者的硅中心均处于畸变四面体配位环境中。