The Synthesis of Tris(silyl)silanides Revisited. A Study of Reactivity and Stability

In this contribution, we investigated the stability of (H₃Si)₃SiLi (2a) in the presence of tetramethylethylenediamine (TMEDA) and 1,2-bis(diphenylphosphino)ethane (DPPE). Moreover, the synthesis to obtain tris(silyl)silanides with alternated counter ions by the base mediated desilylation approach was described. Additionally, metal-metal exchange reactions of 2 a with MgBr₂, ZnCl₂, HgCl₂ were examined. Subsequently, we reacted 2 a with 1.0 and 0.5 equivalents of ZnCl₂[TMEDA] and could obtain the isolable zinc substituted silanides 5 a,b. Finally, we reacted 2 a with equimolar amounts of [(^MesNacnac)MgI(OEt₂)] and [(^DippNacnac)MgI(OEt₂)] and found the selective transmetalation to the corresponding magnesium substituted silanides 6 a,b in good yields. Interestingly, for compounds 5 a,b and 6 a,b the removal of the reaction solvents did not induce a degradation. For compound 6 a crystals suitable for X-ray analysis could be grown, which represents the first structural characterization of an isolable perhydrogenated hypersilanide.