Silyl alkali metals

Certain reactions of silyl—alkali metal compounds, such as coupling of (CH3) (C6H5)3 BSiLi with appropriate chlorosilanes (51) and hydrolysis of [(CH3)3Si]3SiLi (63), lead to the formation of organopolysilanes with the silicon-hydrogen bond. There have been few reports of such synthesis. 

C. Reaction of a Silyl Alkali-Metal Compound with a Metal Halide. .. 11... 

The method is of limited applicability, since although silyl alkali metal compounds RaSiM are known when RaSi is H2n+iSin (n = 1-5), Me2n+iSi in = 1, 3, 4), and Me Ph3-nSi (n = 0-2), and several dilithium derivatives Li(SiPh2) Li (n = 4-6) have also been described, all are rather difficult to prepare and handle (24). It will be seen that only some of them have yet been used to prepare silicon-transition-metal compounds. 

Reactions of Silyl Alkali Metal Compounds with Metal Halides... 

Although this is a potentially widely useful preparative method, especially for the synthesis of A-type silylene-bridged complexes, only two types of reactions are reported. One is the reaction of silyl-alkali metal derivatives... 

SUyl anions (silyl-alkali metal derivatives) have been prepared as described in equations (15-17). Reactions of triphenylsilyl anions with electrophiles give the expected products. SUyl anions have a considerable configurational stabUity (equation 64). 

Formation of Silicon-Transition and Inner Transition-Metal Bond 243 S.8.3.4. from Silyl-Alkali Metal Reagents... 

Bis-silyl derivatives of these Group 12 metals are readily accessible and thermally stable, and can be good precursors to the corresponding silyl-alkali metals via metal-metal exchange reaction. 

Borane Silyl-alkali metal T (°C) Time (h) Product Yield (%) Ref. 

Silyl-alkali-metal reagents with Al metal and organoaluminum halides lead to silyl-Al compounds. The best results are, e.g., using K[SiHj] with n-BujAlCl in... 

The intermediate of the reaction may be the silyl-alkali metal species, so that the reaction of the silyl-alkali metal derivatives with chlorosilane resulted in the formation of the silicon-silicon bonded compound (equation 58). 

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