LiNSiMe32

LiNSiMe32, or lithium bis(trimethylsilyl)amide, is a lithium amide in which nitrogen bears two trimethylsilyl substituents. It is a white to off-white solid that is highly moisture- and air-sensitive. In common coordinating solvents such as tetrahydrofuran (THF) or diethyl ether, it acts as a strong, non-nucleophilic base and is widely used to deprotonate weak acids and to generate organolithium reagents in situ. It is incompatible with water and oxygen, hydrolyzing to amide and silanol species and releasing heat.

Preparation: It is typically prepared by deprotonation of hexamethyldisilazane ((Me3Si)2NH) with n-butyllithium in hydrocarbon solvents, yielding LiN(SiMe3)2 and butane as a by-product.

Applications: widely employed as a general base in organic synthesis, for deprotonation to form carbanions and enolates, and for generating lithiation equivalents in situ. It is also used in procedures involving silyl-protecting group strategies or as a precursor to other organolithium species. Reactions using LiN(SiMe3)2 are usually conducted at low temperatures and under inert atmosphere due to its high basicity and moisture sensitivity.

Handling and safety: extremely moisture- and air-sensitive; stored under inert gas. Reacts with water and CO2 to form silanamide and LiOH; contact with skin or eyes may cause irritation. Use proper personal protective equipment and perform handling in a glovebox or on a Schlenk line to minimize exposure.