Sodium triacetoxyborohydride
Sodium triacetoxyborohydride, also known as sodium triacetoxyhydroborate, commonly abbreviated STAB, is a chemical compound with the formula Na3BH. 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:
Sodium triacetoxyborohydride is a milder reducing agent than sodium borohydride or even sodium cyanoborohydride. It reduces aldehydes but not most ketones. It is especially suitable for reductive aminations of aldehydes and ketones.
However, unlike sodium cyanoborohydride, the triacetoxyborohydride hydrolyzes readily, nor is it compatible with methanol. It reacts only slowly with ethanol and isopropanol and can be used with these.
NaBH3 may also be used for reductive alkylation of secondary amines with aldehyde-bisulfite adducts.
