Sodium bis(trimethylsilyl)amide


Sodium bisamide is the organosilicon compound with the formula 2NNa. This species, usually called NaHMDS, is a strong base used for deprotonation reactions or base-catalyzed reactions. Its advantages are that it is commercially available as a solid and it is soluble not only in ethers, such as THF or diethyl ether, but also in aromatic solvents, like benzene and toluene by virtue of the lipophilic TMS groups.
NaHMDS is quickly destroyed by water to form sodium hydroxide and bisamine.

Structure

Although the N-Na bond is polar covalent as a solid, when dissolved in nonpolar solvents this compound is trimeric, consisting of a central Na3N3 ring.

Applications in synthesis

NaHMDS is used as a base in organic synthesis. Typical reactions:
NaHMDS is also used as a base to deprotonate other compounds containing weakly acidic O-H, S-H, and N-H bonds. These include cyanohydrins and thiols.
NaHMDS is reagent to convert alkyl halides to amines in a two step process that begins with N-alkylation followed by hydrolysis of the N-Si bonds.
This method has been extended to aminomethylation via the reagent 2NCH2OMe, which contains a displaceable methoxy group.