It is a colourless salt used in organic synthesis for chemical reduction including that of imines and carbonyls.

The electron-withdrawing cyanide substituent draws electron density away from the negatively charged boron; thus, reducing the electrophilic capabilities of the anionic component.

[7] Since sodium cyanoborohydride is a mild reducing agent, it gives good chemoselectivity for reaction with certain functional groups in the presence of others.

For example, sodium cyanoborohydride is generally incapable of reducing amides, ethers, esters and lactones, nitriles, or epoxides.

Georg Wittig was the first to synthesize a cyanoborohydride by treating lithium borohydride with hydrogen cyanide in 1951.

[10] The synthesis was later refined to use sodium cyanide and borane in THF making the process safer.