Carbonyl groups, including aldehydes, ketones and glyoxals, react with amines to form Schiff base intermediates that are in equilibrium with their free forms. The labile Schiff’s base interaction can be stabilized by chemical reduction. If the Schiff’s base is formed between an aldehyde and an amine then sodium cyanoborohydride is routinely used for the reduction of the Schiff’s base to a covalent bond1 .
Sodium cyanoborohydride is preferred as a reducing agent over sodium borohydride as the latter will also reduce the reactive aldehydes to hydroxyls at the same time as reducing the Schiff’s bases. The cyanoborohydride offers five times milder reduction compared to borohydride in the reductive amination process, reducing the Schiff’s bases, but not the aldehydes2. The reductive amination process is pH-dependent, being more efficient in acidic conditions, especially at high pH.
- Synonym: Sodium cyanotrihydridoborate
- Linear formula: NaCNBH3
- CAS # 25895-60-7
- Molecular weight: 62.84
- Form: White to yellow crystalline powder
- Reduction of Schiff's base
- Conjugation of aldehydes and amines
- Conjugation of hydrazides and amines
- Coupling enymes to antibodies
- Coupling protein/peptides to activated agaroses