Tetra-n-butylammonium hydroxide, 40% w/w in methanol is used as a phase-transfer catalyst in organic synthesis especially for alkylation and condensation reactions. It is also used as a curing accelerator for epoxy resins.
Tetrabutylammonium hydroxide solution 1M in methanol) may be used as a base to synthesize ring methyl and methylene deuteriated porphyrins and metalloporphyrins. It may also be used as an initiator of graft polymerization between pivalolactone and poly(ethylene-co-vinyl acetate-co-methacrylic acid
Tetrabutylammonium hydroxide is a quaternary ammonium salt mainly used as a strong base and phase-transfer catalyst.