(2-Ammonioethyl)di-t-butylphosphonium bis(tetrafluoroborate) is primarily used in organic synthesis and catalysis. It serves as a phase-transfer catalyst, facilitating reactions between reactants in different phases, such as aqueous and organic layers. This compound is particularly effective in enhancing reaction rates and yields in nucleophilic substitution reactions, esterifications, and alkylations. Its unique structure allows for efficient transfer of anions, making it valuable in the production of pharmaceuticals, agrochemicals, and specialty chemicals. Additionally, it is utilized in electrochemical applications due to its ionic properties and stability under various conditions.