Sodium triacetoxyborohydride

Chemical compound From Wikipedia, the free encyclopedia

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:[2]

Na[BH4] + 3 CH3COOH → Na[(CH3COO)3BH] + 3 H2
Quick facts Names, Identifiers ...
Sodium triacetoxyborohydride
Sodium_triacetoxyborohydride
Sodium_triacetoxyborohydride
Names
IUPAC name
Sodium tris(acetato-kappaO)(hydrido)borate(1-)
Other names
  • Borate(1-), tris(acetato-kappaO)hydro-, sodium (1:1), (T-4)-
  • STAB
  • STABH
  • Sodium triacetoxyhydroborate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.115.747 Edit this at Wikidata
EC Number
  • 611-401-0
UNII
UN number 1409
  • InChI=1S/C6H9BO6.Na/c1-4(8)11-7(12-5(2)9)13-6(3)10;/h1-3H3;/q-1;+1
    Key: AGGHKNBCHLWKHY-UHFFFAOYSA-N
  • [BH-](OC(=O)C)(OC(=O)C)OC(=O)C.[Na+]
Properties
Na[(CH3COO)3BH]
Molar mass 211.94 g·mol−1
Appearance White powder
Density 1.36 g/cm3 (20.1 °C (68.2 °F; 293.2 K))[1]
Melting point 116–120 °C (241–248 °F; 389–393 K)[1] decomposes
decomposition
Solubility 1,2-dichloroethane, dichloromethane, dioxane, methylene chloride, tetrahydrofuran, toluene,[2] benzene, dimethyl sulfoxide[3]
log P -2.88[4]
Structure
4 at boron atom
Tetrahedral at boron atom
Hazards
GHS labelling:[1]
GHS02: FlammableGHS05: CorrosiveGHS07: Exclamation markGHS08: Health hazard
Danger
H228, H260, H302, H318, H360FD
P201, P202, P210, P223, P231+P232, P240, P241, P264, P270, P280, P301+P312+P330, P305+P351+P338+P310, P308+P313, P335+P334, P370+P378, P402+P404, P405, P501
NFPA 704 (fire diamond)
[4]
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
2
2
2
W
360 °C (680 °F; 633 K)[1]
Related compounds
Other anions
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)
Close

Comparison with related reagents

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.[5][6][7]

However, unlike sodium cyanoborohydride, sodium triacetoxyborohydride quickly decomposes upon contact with methanol. It reacts only slowly with ethanol and isopropanol and therefore can be used with these solvents.[6]


Reductive amination with STAB
Reductive amination with STAB

NaBH(OAc)3 may also be used for reductive alkylation of secondary amines with aldehyde-bisulfite adducts. [8]

Monoacetoxyborohydride

The combination of Na[BH4] with carboxylic acids results in the formation of acyloxyborohydride species other than sodium triacetoxyborohydride. These modified species can perform a variety of reductions not normally associated with borohydride chemistry, such as alcohols to hydrocarbons and nitriles to primary amines.[9]

References

Related Articles

Wikiwand AI