Metal-containing compounds, Silicon Tris

Compounds containing Silicon-, Germanium-, Tii, and Lead-Nitrogen Bonds.—Molecular nitrogen is reductively silylated by MeaSiCl and lithium metal in the presence of a transition-metal catalyst to give tris(trimethyl-silyl)amine [reaction (101)]. Variable-temperature n.m.r. spectra for a number of compounds containing Si—N bonds in which potentially diastereo-... 

At the turn of the 18th century many scientists believed that silica, or silica earth, contained an unknown chemical element and tried to isolate it in a free state. H. Davy attempted to decompose silica with an electric current—the method by which a number of alkali metals had already been prepared—but without success. The scientist s attempt to prepare free silicon by passing metallic potassium vapour over red-hot silicon oxide also failed. In 1811 L.J. Gay Lussac and L. Thenard applied themselves to the problem. They observed a vigorous reaction between silicon tetra-fluoride and metallic potassium a reddish brown compound was formed in the reaction. The scientists could not reveal the nature of the product most likely, it was contaminated amorphous silicon. 

The metallation of thiophen and 2- and 3-methylthiophen with butylcaesium and butylpotassium has been studied. Thienylcopper reagents have been used for the synthesis of iodo-thiophens. Thienyltin(iv) compounds have been prepared. The chemistry of thienyl-lead(iv)tricarboxylate has been investigated. The cleavage of the thiophen-silicon bond in tris(trichloro-2-thienyl)-methylsilane with butyl-lithium to give thienyl-lithium derivatives has been achieved. Considerable work on the synthesis and reactions of compounds containing thiophen-phosphorus bonds has appeared/ " and the reactions with a/S-unsaturated acid derivatives have been extensively studied. ... 

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