The syntheses and structures of organosilicon lithium compounds have been the subject of much interest. Recently a few dilithiosilyl compounds including their synthetic applications and ab initio calculation, etc. were reported. However, trilithiosilane has not been reported yet. Last ten years we have synthesized stable halosilylenoids and dilithiohalosilanes formed from the reduction of trihalosilanes with strong reducing agents. These results prompted us to investigate a synthesis of trilithiosilanes.
The reaction of trihalo[tris(trimethylsilyl)methyl]silane (TsiSiX3, Tsi=C(SiMe3)3, X=Br, Cl) with more than 6 equivalents of lithium naphthalenide (LiNp) in THF at -78℃ gave trilithiosilane together with halodilithiosilane and halolithiosilane which are indirectly monitored by GC/MS after adding excess MeOH into reaction mixture. Transmetalation of lithiosilanes with MgBr2 and their thermal stability were also investigated. In this presentation, synthesis of trilithiosilane and its transmetalation will be discussed in detail.