SYNTHESIS OF ORGANOSILYL COMPOUNDS CONTAINING FERROCENE NUCLEI

In order to investigate the effect of addition of ferrocene moiety to the heat-oxidation stability of silicon oil, a series of organosilyl compounds containing ferrocene nuclei was synthesized. Original attempts to couple two molecules of trimethylsilylcyclopentadiene with FeCl~2 in the presence of diethylamine to form 1,1'-bis (trimethylsilyl) ferrocene failed, due to the breakage of Si-C bond, ferrocene was obtained.Two methods for the synthesis of bisorganosilyl substituted ferrocene were studied.Method 1:Reaction of 1, 1'-bissodium ferrocene with trialkylsilylchloride, gave 1, 1'-bis (trimethylsilyl) ferrocene,1, 1'-bis (tributylsilyl) ferrocene and 1, 1'-bis (dimethylphenylsilyl) ferrocene. For the preparation of monosubstituted ferrocene, Li-ferrocene was employed. However, the products were always a mixture of mono- and disubstituted ferrocenes which were diffioult to separate. In order to circumvent the difficulty, limited amount of organosilyl chloride was used and pure mono-substituted vinyldiethylsilylferrocene was obtained.Method 2: The addition of Grignard reagent of trimethyl-γ-chloropropylsilane to bis-acetylferrocene gave bis-tert-alcohol containing ferrocene nuclei.