Sodium triacetoxyborohydride, also known as sodium triacetoxyhydroborate, commonly abbreviated STAB, is a chemical compound with the formula Na(CH3COO)3BH. Like other borohydrides, it is used as a reducing agent in organic synthesis. This colourless salt is prepared by protonolysis of sodium borohydride with acetic acid: NaBH4 + 3 HO2CCH3 → NaBH(O2CCH3)3 + 3 H2 Owing to the steric and electronic effects of the acetoxy groups, sodium triacetoxyborohydride is a milder reducing agent than sodium borohydride or even sodium cyanoborohydride. Furthermore, NaBH(OAc)3 avoids the toxic side-products generated by sodium cyanoborohydride. Sodium triacetoxyborohydride is especially suitable for reductive aminations of aldehydes and ketones. However, unlike sodium cyanoborohydride, the triacetoxyborohydride is water-sensitive, and water cannot be used as a solvent with this reagent, nor is it compatible with methanol. It reacts only slowly with ethanol and isopropanol and can be used with these. NaBH(OAc)3 may also be used for reductive alkylation of secondary amines with aldehyde-bisulfite adducts.