Silyl aluminates

Reaction of methanetellurol with lithium aluminum hydride in diethyl ether caused liberation of hydrogen and formation of lithium tetrakis[methyltelluro]aluminate. This compound was not isolated but reacted with silyl or germyl halides to give silyl or germyl methyl tellurium derivatives4. 

Lithium tetrakis[methyltelluro]aluminate, prepared from methanetellurol and lithium aluminum hydride, reacted with silyl, germyl, and stannyl halides at low temperatures to produce, for instance, methyl silyl tellurium derivatives1. 

The silyl halides can now" be prepared in high purity and high yield by the facile hydrogen halide cleavage of the carbon-silicon bond in arylsilanes. " No catalyst is required, and the use of the hazardous intermediate reagent, silane, is avoided. Bromosilane is prepared by the reaction of hydrogen bromide and phenylsilane. The latter is obtained by lithium hydro-aluminate reduction of the commercially available phenyltri-chlorosilane. lodosilane can be prepared in a similar fashion however, mixtures of iodosilane and benzene are difficult to separate. The preferred alternative procedure described below utilizes an isomeric mixture of 2-, 3-, and 4-chlorophenylsilanes as the intermediate. This intermediate is obtained by the chlorination of phenyltrichlorosilane, and is then reduced to the hydride. 

The silyl organoaluminum reagent (52) was prepared either by the addition of activated aluminum to a tetrahydrofuran solution of chlorotrimethylsilane, or by the treatment of sodium tetrakis(trimethyl-silyl)aluminate with aluminum chloride. Alternatively, ate complex (53) may be prepared by the addition of methyllithium to tris(trimethylsilyl)aluminum. ... 

Treatment of cyclopropanecarbonyl chloride with excess of lithium tetrakis(trimethyl-silyl)aluminate in the presence of a catalytic amount of copper(I) cyanide gave cyclopropyl-carbonyltrimethylsilane in 89% yield. 

Coordination polymerization of hydroxyl, carboxyl and amino monomers can also be effected by the judicious use of protecting groups. For example, amino and hydroxyl monomers have been protected by silyl ethers and aluminate salts for Ziegler Natta and/or metallocene polynrierization and carboxyl monomers have been protected via aluminate salts. Alternatively, organoborane synthons have been used to carry... 

The formation and characterization of rare-earth Ln-OR (R = aryl-, alkyl-, or silyl-) alkyl aluminate complexes have been reviewed [112,113]. These complexes are essentially accessible via two routes (1) alkylaluminum adduct formatiOTi starting from a homoleptic rare-earth aryl(alk)oxide precursor and (2) protmiolysis of the corresponding phenol/alcohol/silanol source by alkane eUmination. The outcome of the reaction between homoleptic aryl(alk)oxides with AlMe3 is determined by the bulkiness of the aryl(alk)oxide ligand (Scheme 26) [133], In the resulting dinuclear complexes, the TMA units are linked through (p-OR) and (p-Me) bridges. 

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