Organosilyl Compounds of Boron, Aluminium, Gallium, Indium and Thallium

3 Organosilyl Compounds of Boron, Aluminium, Gallium, Indium and Thallium 

Organosilyl alkali metals, especially organosilane lithium, are also used (Eq. 3.235)  

The organosilyl compounds of Al, Ga, In and T1 are not as stable as those of B. Tris(trimethylsilyl)aluminium can be prepared in solvated form from chlorotrimeth-ylsilane and Li/Al in THF/benzene, in the presence of a small amount of mercury. It may also be prepared from [(H3Q3Si]2Hg and aluminium in THF [445] (Eq. 3.238)  

Lithium tetrakis(trimethylsilyl) aluminate [445] LiAl[(H3C)3Si]4-2DME (m.p. 93 °C), which is relatively stable, has been prepared in 44 % yield from Al, Si, Hg and chlorotrimethylsilane in DME/TMF. Non-solvated NaAl[(H3C)3Si]4 was obtained in similar fashion. This compound reacts with aluminium chloride in pentane at 25 °C to form solvent-free tris(trimethylsilyl)aluminium [446] (47% m.p. 60°C (dec.)) (Eq. 3.239)  

The solvated lithium tetrasilylgallate salt can be prepared similarly, and like the aluminium compound, it is spontaneously inflammable in air. 

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