Unexpected Formation of NHC-Stabilized Hydrosilylyne Complexes via Alkane Elimination from NHC-Stabilized Hydrido(alkylsilylene) Complexes

N-heterocyclic carbene (NHC)-stabilized hydrosilylyne complex Cp*­(CO)2WSiH­(MeIMe)2 (3a) (MeIMe = 1,3,4,5-tetramethylimidazole-2-ylidene) was formed by the reaction of an NHC-stabilized silylene complex Cp*­(CO)2(H)­WSiH­(MeIMe)­{C­(SiMe3)3} (2a) with 1 equiv of MeIMe at 70 °C. In this reaction, HC­(SiMe3)3 was unexpectedly eliminated from 2a. A C5Me4Et analogue of 3a, (C5Me4Et)­(CO)2WSiH­(MeIMe)2 (3b), was also synthesized by the same method, and the structure of 3b was confirmed by X-ray crystallography. Although the silicon center of 3b is coordinated by two NHCs, the length of the W–Si bond of 3b [2.363(4) Å] is as short as that of the shortest WSi double bond (∼2.36 Å). These complexes, 3a and 3b, are the first examples of a base-stabilized silylyne complex having only a hydrogen on the silicon atom.N-杂环卡宾（N-heterocyclic carbene, NHC）稳定化的氢硅炔配合物Cp*(CO)₂WSiH(MeIMe)₂（3a，其中MeIMe=1,3,4,5-四甲基咪唑-2-亚基）可通过N-杂环卡宾稳定化的硅烯配合物Cp*(CO)₂(H)WSiH(MeIMe){C(SiMe₃)₃}（2a）与1当量的MeIMe在70℃下反应制得。该反应中，HC(SiMe₃)₃意外地从2a中脱除。3a的C5Me4Et类似物(C5Me4Et)(CO)₂WSiH(MeIMe)₂（3b）也通过相同方法合成，其结构经X射线晶体学验证。尽管3b的硅中心被两个NHC配体配位，但其W-Si键长[2.363(4) Å]与最短的W=Si双键（约2.36 Å）的键长相当。上述3a和3b是首例在硅原子上仅连有氢原子的碱稳定化氢硅炔配合物。