Tetrabutylammonium salicylate is primarily used as a phase-transfer catalyst in organic synthesis, facilitating the transfer of reactants between immiscible phases, such as aqueous and organic layers. It is particularly effective in reactions involving the synthesis of complex organic molecules, where it enhances reaction rates and yields. Additionally, it finds application in the preparation of ionic liquids, which are used as solvents or electrolytes in various chemical processes. Its role in polymerization reactions is also notable, where it helps in controlling the molecular weight and distribution of polymers. Furthermore, it is employed in analytical chemistry as a reagent for the detection and quantification of specific ions or compounds.