Sodium triacetoxyborohydride

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Sodium triacetoxyborohydride
Names
IUPAC name
Sodium triacetoxyborohydride
Other names
NaBH(OAc)3
STAB
STABH
Properties
C6H10BNaO6
Na(CH3COO)3BH
Molar mass 211.94 g/mol
Appearance White solid
Odor Odorless
Density 1.20 g/cm3
Melting point 116–120 °C (241–248 °F; 389–393 K) (decomposition)
Boiling point Decomposes
Reacts
Solubility Soluble in DMF
Slightly soluble in THF
Insoluble in chloroform
Hazards
Safety data sheet Sigma-Aldrich
Lethal dose or concentration (LD, LC):
500 mg/kg (rat, oral)
Related compounds
Related compounds
Sodium borohydride
Sodium cyanoborohydride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

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.

Properties

Chemical

Sodium triacetoxyborohydride is a milder reducing agent than sodium borohydride or even sodium cyanoborohydride. It can reduce aldehydes but does not reduce most ketones. It is especially suitable for reductive aminations of aldehydes and ketones.

However, unlike sodium cyanoborohydride, the triacetoxyborohydride hydrolyzes readily in water, and also reacts with methanol. It also reacts with ethanol and isopropanol, albeit much slower.

STABH may also be used for reductive alkylation of secondary amines with aldehyde-bisulfite adducts.

Physical

Sodium triacetoxyborohydride is a white hygroscopic solid.

Availability

STAB is sold by chemical suppliers.

Preparation

Sodium triacetoxyborohydride can be prepared by protonolysis of sodium borohydride with acetic acid:[1]

NaBH4 + 3 HO2CCH3 → NaBH(O2CCH3)3 + 3 H2

Projects

  • Reducing agent

Handling

Safety

Sodium triacetoxyborohydride hydrolyzes in water to release hydrogen, which is flammable.

Storage

Should be kept in airtight bottles, or in a desiccator.

Disposal

Can be neutralized by careful hydrolysis.

References

  1. Gordon W. Gribble, Ahmed F. Abdel-Magid, "Sodium Triacetoxyborohydride" Encyclopedia of Reagents for Organic Synthesis, 2007, John Wiley & Sons.

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