Sodium cyanoborohydride is widely used as a selective reducing agent in organic synthesis. It is particularly effective in reductive amination reactions, where it reduces imines or iminium ions to amines without affecting other functional groups. This makes it valuable in the synthesis of pharmaceuticals, agrochemicals, and other complex organic molecules. It is also employed in the stabilization of sensitive intermediates during multi-step reactions. Additionally, it finds application in biochemical processes, such as the modification of proteins and nucleic acids, where its mild reducing properties are advantageous.