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[[es:Cianoborohidruro de sodio]]
[[es:Cianoborohidruro de sodio]]
[[fr:Cyanoborohydrure de sodium]]
[[fr:Cyanoborohydrure de sodium]]
[[ja:シアノ水素化ホウ素ナトリウム]]
[[nl:Natriumcyanoboorhydride]]
[[nl:Natriumcyanoboorhydride]]
[[zh:氰基硼氢化钠]]
[[zh:氰基硼氢化钠]]

Revision as of 11:52, 12 March 2010

Sodium cyanoborohydride
Sodium cyanoborohydride
Names
Other names
Sodium cyanotrihydridoborate
Identifiers
ECHA InfoCard 100.043.001 Edit this at Wikidata
EC Number
  • 247-317-2
Properties
NaBH3CN
Molar mass 62.84 g/mol
Appearance white to off-white powder, hygroscopic
Density 1.20 g/cm3
Melting point 241 °C decomp.
soluble
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
3
2
2
Related compounds
Other anions
Sodium borohydride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium cyanoborohydride is the inorganic compound with the formula NaBH3(CN). This colourless salt is widely used in organic synthesis for the reduction of imines.

Preparation and use

The reagent may be prepared, either by treating sodium cyanide with borane, or by reacting sodium borohydride with mercuric cyanide. Owing to the presence of the electron-withdrawing cyanide substituent, [B(CN)H3] is far less nucleophilic than is [BH4], as found in sodium borohydride.[1]

Sodium cyanoborohydride is a mild reducing agent that converts imines to amines. It can be used to exchange the oxygen for an amine group on the carbonyl carbon of aldehydes or ketones when reacted with ammonia or a primary amine. Selectivity is achieved at mildly basic solutions (pH 7-10). Owing to this selectively, the reagent is ideal for reductive aminations. This reduction is known sometimes as the Borch Reaction.[2] The salt is mildly water-sensitive, but tolerates aqueous conditions.[3] In addition, sodium cyanoborohydride is often used in hydrogenolysis reactions, such as the opening of acetals.

References

  1. ^ Ellen W. Baxter, Allen B. Reitz Reductive Aminations of Carbonyl Compounds with Borohydride and Borane Reducing Agents in Organic Reactions, 2002, John Wiley and Sons. doi:10.1002/0471264180.or059.01
  2. ^ Richard F. Borch and Mark D. Bernstein and H. Dupont Durst (1971). "Cyanohydridoborate Anion as a Selective Reducing Agent". J. Am. Chem. Soc. 93 (12): 2897–2904. doi:10.1021/ja00741a013.
  3. ^ Timothy M. Beard and Nicholas J. Turner (2002). "Deracemisation and Stereoinversion of alpha-Amino Acids Using D-Amino Acid Oxidase and Hydride Reducing Agents". Chemical Communications (3): 246–7.