Phase Transfer Catalysts

Benzyltriethylammonium chloride is one of most commonly used phase transfer catalysts. TEBA has been used extensively in the formation of carbenes in heterogeneous systems. 

Together with benzyltriethylammonium salt, benzyltrimethylammonium hydroxide is a popular phase-transfer catalyst. It is used in aldol condensation reactions and base-catalyzed dehydration reactions. It is also used as a base in Ando's Z-selective variant of Horner-Wadsworth-Emmons Olefination reactions.

Tetrabutylammonium hydrogensulfate may be employed as a catalyst for the green synthesis of glycosyl 1,4-dihydropyridines. It participates as a cocatalyst in the reaction medium for the preparation of alternating polyketones and propionic acid.