 Lithium hexamethyldisilazide

Lithium hexamethyldisilazide is the lithium salt of $\mathrm{N}(\mathrm{SiM}{\mathrm{e}}_3{)}_2^{-}$, a bulky amide anion. It is used as a strong base for transformations such as enolate formation.

The lithium ion can coordinate oxygen donors and organize aggregates. Consequently, calling the reagent non-nucleophilic is a useful comparison under specified conditions, not a claim that it cannot participate in any competing reaction.