Boron Hydrides, Heteroboranes, and their Metalla Derivatives (Commercial Aspects)

Abstract

Sodium tetrahydroborate, NaBH 4 , more commonly called sodium borohydride, is the most widely used commercial boron hydride. Sodium borohydride is available as a 12% solution in caustic soda and in solid form either as powder or pellets. Solid sodium borohydride does not ignite upon contact with moisture and is not shock‐sensitive. These characteristics allow it to be handled safely in air. Because it does liberate hydrogen upon contact with water it should be handled with care. The predominant use for sodium borohydride is in wood pulp bleaching. The next largest commercial use is as a reducing agent of functional groups in organic synthesis. A significant application in pharmaceutical synthesis is the stereospecific and selective reduction in steroid production. Borane complexes are the most widely used commercial boron compounds, after sodium borohydride. Examples used in organic synthesis are amine borane complexes and borane complexes of tetrahydrofuran and dimethyl sulfide. Although not commercial as yet, boron neutron capture therapy (bnct) involves the uptake of boron compounds enriched with the boron‐10, 10 B, isotope, selectively accumulating in cancerous tumors.