Used as a phase transfer catalyst in organic synthesis, facilitating reactions between compounds in different phases by shuttling ions into organic solvents. Commonly applied in nucleophilic substitutions and esterifications where improved reaction rates and yields are needed. Also utilized in the preparation of ylides for Wittig reactions, enabling efficient carbon-carbon bond formation. Its lipophilic character enhances membrane permeability, making it suitable in some biochemical applications for ion transport studies.