Sodium triacetoxyborohydride (STAB) is a selective reducing agent commonly used in organic synthesis, particularly for the reductive amination of aldehydes and ketones with amines. It is milder than other reducing agents like sodium borohydride (NaBH₄) and is often preferred due to its selectivity and tolerance of a wide range of functional groups.
Chemical Structure and Properties
Chemical Name: Sodium triacetoxyborohydride
Molecular Formula: C₆H₁₀BNaO₆
Molecular Weight: 211.95 g/mol
CAS Number: 56553-60-7
Physical Properties:
Sodium triacetoxyborohydride is composed of a borohydride (BH₄) core stabilized by three acetoxy groups (-OCOCH₃), which reduce its reactivity compared to sodium borohydride. This modification allows the reagent to be more selective, especially in the presence of aldehydes, amines, and ketones.
Synthesis
Sodium triacetoxyborohydride is typically synthesized by reacting sodium borohydride (NaBH₄) with acetic acid or acetyl chloride. The reaction leads to the formation of the acetoxy groups that modify the borohydride, making it less reactive but still effective in selective reductions.
Chemical Structure and Properties
Chemical Name: Sodium triacetoxyborohydride
Molecular Formula: C₆H₁₀BNaO₆
Molecular Weight: 211.95 g/mol
CAS Number: 56553-60-7
Physical Properties:
| Property | Description |
|---|---|
| Appearance | White to off-white crystalline powder |
| Solubility | Soluble in acetonitrile, DMF, DCM; reacts with water |
| Melting Point | 116-120°C |
| Stability | Stable under dry conditions, decomposes in moist environments |
| Storage Conditions | Store in a cool, dry place away from moisture |
Synthesis
Sodium triacetoxyborohydride is typically synthesized by reacting sodium borohydride (NaBH₄) with acetic acid or acetyl chloride. The reaction leads to the formation of the acetoxy groups that modify the borohydride, making it less reactive but still effective in selective reductions.