Preparation and properties of trimethylsilylated cyclosiloxazanes: a new anionic rearrangement of N-lithiocyclosiloxazanes

Cyclosiloxazanes having NH groups can be N-lithiated with butyl-lithium. Some of the lithium derivatives rearrange with a contraction of the ring and formation of one or more SiOLi side-chains. The derivatives, normal and rearranged, react with chlorotrimethylsilane to give the corresponding trimethylsilyl compounds, the i.r. and n.m.r. spectra, and hydrolytic and thermal stability of which are described.