Tetrabutyl ammonium acetate, combined with acetic acid, is widely used in organic synthesis as a phase-transfer catalyst. It facilitates the transfer of reactants between immiscible phases, enhancing reaction rates and yields. This combination is particularly effective in nucleophilic substitution reactions, esterifications, and alkylations.

In analytical chemistry, it serves as an ion-pairing agent in liquid chromatography, improving the separation and detection of various compounds. Its application extends to the preparation of ionic liquids, which are used in green chemistry for their low volatility and high thermal stability.

Additionally, it is employed in the synthesis of pharmaceuticals and fine chemicals, where precise control over reaction conditions is crucial. Its role in promoting efficient and selective reactions makes it a valuable reagent in both industrial and research settings.