liimides

Liimides is not a widely standardized term in chemical nomenclature. When used, it typically refers to lithium salts of imide ligands—often called lithium imides—derived from imide skeletons such as phthalimide, succinimide, or related compounds. In these species, the imide moiety features a nitrogen-flanked carbonyl system, and deprotonation at nitrogen yields a monoanionic imide that coordinates Li+ through the carbonyl oxygens and nitrogen.

Synthesis and structure: Liimides are commonly prepared by deprotonation of the parent imide with strong organolithium bases (for example, butyllithium or other lithium amide bases) in inert solvents. The resulting lithium imide salts typically exist as solids or in solution with coordination of Li+ to the imide oxygens. Lithiation can be selective at nitrogen, producing salts such as lithium phthalimide for many standard substrates.

Reactivity and uses: Liimides act as strong bases and can serve as modest nucleophiles in substitution or cyclization reactions. A prominent example is lithium phthalimide, which is used in the Gabriel synthesis to form N-alkyl phthalimides; subsequent hydrolysis affords primary amines. Other lithium imide salts can transfer the imide fragment in synthetic sequences or function as precursors to more complex imide-containing structures in polymer chemistry or organic synthesis.

Applications and safety: These reagents are mainly encountered in organic synthesis and related fields. They are typically moisture- and air-sensitive and are prepared and used under inert atmospheres due to the reactivity of organolithium compounds. Handling requires appropriate safety precautions for pyrophoric and reactive reagents.

See also: imides; lithium salts; Gabriel synthesis; lithium phthalimide.