Stereospecific synthisis of 2,3-dihydro-2-metallaphenalenes, meso-[M(η-C5H5)2R2][M = Zr, Hf; R2=(CHSiME3)2C10H6], via an unstable dilithium reagent, [R2{Li(tmeda)}2](tmeda = tetramethyl-ethylenediamine), which is coverted the complex [CHSiME2C(SiMe3)C10H6][Li(tmeda)]2 containing a silicon heterocycle dicarbanion

Abstract

In situ Grignard reactions of 1,8-(ClCH₂)₂C₁₀H₁₀H₆ have yielded 2,3-dihydro-2,2-dimethyl-2-silaphenalene, which can be selectively momolithiated at the 1-position, and 1,8-(Me₃SiCH₂)₂C₁₀H₆, a compound readily dilithiated and subsequuently converted into the zirconium and hafnium metallacycles, meso-[M(η-C₅H₅)₂(CHSiME₃)₂C₁₀H₆]; the dilithium complex is converted into the complex [[graphic omitted]C₁₀H₆][Li(tmeda)]₂ containing a silicon heterocycle dicarbanion and characterized as the substituted silaphenalene, the same product as the ClSiMe₃ adducts of momo-lithiated silaphenalene.