Novel η³-1-Silaallyl Tungsten Complexes via Si−H Bond Activation of Hydrovinylsilanes: Structure and Reactivity toward Methanol

Reactions of cis-Cp*(CO)2W(MeCN)Me (1) with HSiMe2(CHCR2) (R = H, Me) afford the novel η3-1-silaallyl complexes Cp*(CO)2W(η3-Me2SiCHCR2) [R = H (2), Me (3)] accompanied by liberation of MeCN and CH4 via thermal Si−H bond activation. η3-Coordination and exo conformation of the 1-silaallyl ligand in 3 are shown by X-ray crystal analysis, which reveals the partial double bond character of the Si−C bond (1.800(4) Å) in the silaallyl moiety. Complexes 2 and 3 show extremely high reactivity toward MeOH to give the hydrido-(methoxysilyl)alkene complex trans-Cp*(CO)2WH(η2-MeOMe2SiCHCH2) (4) and the four-membered metallacycle (6), respectively.顺式-Cp*(CO)₂W(CH₃CN)Me（化合物1）与HSiMe₂(CH=CR₂)（R=H、Me）发生反应，得到新型η³-1-硅杂烯丙基配合物（η³-1-silaallyl complexes）Cp*(CO)₂W(η³-Me₂SiCHCR₂) [R=H（化合物2）、Me（化合物3）]，反应伴随乙腈与甲烷的释放，该过程通过热诱导Si-H键活化（Si−H bond activation）完成。通过X射线晶体衍射分析（X-ray crystal analysis）确认了化合物3中1-硅杂烯丙基配体的η³-配位（η³-coordination）与外型构象（exo conformation），该分析结果揭示了硅杂烯丙基结构单元内Si-C键（键长1.800(4) Å）具有部分双键特性。配合物2与3对甲醇展现出极高的反应活性，分别生成氢(甲氧基硅基)烯烃配合物trans-Cp*(CO)₂WH(η²-MeOMe₂SiCH=CH₂)（化合物4）以及四元金属环配合物（four-membered metallacycle）（化合物6）。