Potassium bis(trimethylsilyl)amide

Description

Potassium bis(trimethylsilyl)amide (KHMDS) is a sterically hindered strong base. It is commercially available as a solid and as a solution in a variety of solvents (ex. THF, 2Me-THF, toluene, and MTBE). Similar reagents include lithium bis(trimethylsilyl)amide (LiHMDS) and sodium bis(trimethylsilyl)amide (NaHMDS).

Chemical properties

Colorless to amber solution

The Uses of Potassium bis(trimethylsilyl)amide

Potassium Bis(trimethylsilyl)amide (1M in THF) is used in the preparation of 5-azacytidine, an antineoplastic drug. Also applied in the preparation of β3-AR agonists used in anti-stress formulations. It is also used as a reagent in the preparation of lanthanide complexes employed in selective cyclization reactions.

The Uses of Potassium bis(trimethylsilyl)amide

To a suspension of the SM (52 mg, 0.2 mmol) in THF (4 mL) was added NaH (60%, 16 mg, 0.4 mmol) at 0 C, and the mixture was stirred for 15 min. To this mixture was added MeI (42 mg, 0.3 mmol) in THF (1 mL) dropwise at 0 C. The reaction mixture was warmed to RT and stirred for 4 h. The mixture was quenched with aq Na2CO3, extracted with EtOAc (3x), and washed with brine. Column purification (20-100% EtOAc/heptane) provided the product as an off-white powder. [31 mg, 60%]

The Uses of Potassium bis(trimethylsilyl)amide

Potassium bis(trimethylsilyl)amide is a strong base used in the alkylation carbonyl compounds.1

The Uses of Potassium bis(trimethylsilyl)amide

Potassium Hexamethyldisilazide is widely used as a Sterically Hindered Base for Enolate Generation in Selective Formation of Linear Conjugated Dienolates and Alkyl (Z)-3-Alkenoates.

Preparation

Potassium Hexamethyldisilazide is prepared and isolated by the procedure of Wannagat and Niederpruem. A more convenient in situ generation from potassium hydride and hexamethyldisilane is described by Brown.

General Description

This product, 1.0 M in 2-methyltetrahydrofuran aligns with "Safer Solvents and Auxiliaries", "Use of Renewable Feedstocks" and "Inherently Safer Chemistry for Accident Prevention".