Diborane-Sodium borohydride

Boron trichloride is used as a catalyst in polymerization reactions. Other applications include refining of alloys soldering flux and as a component in certain fire extinguishers. It also is used to prepare boron libers and other boron compounds including diborane, sodium borohydride and several adducts. 

Reducing agents Aluminum hydride. Bis-3-methyl-2-butylborane. n-Butyllithium-Pyridine. Calcium borohydride. Chloroiridic acid. Chromous acetate. Chromous chloride. Chromous sulfate. Copper chromite. Diborane. Diborane-Boron trifluoride. Diborane-Sodium borohydride. Diethyl phosphonate. Diimide. Diisobutylaluminum hydride. Dimethyl sulfide. Hexamethylphosphorous triamide. Iridium tetrachloride. Lead. Lithium alkyla-mines. Lithium aluminum hydride. Lithium aluminum hydride-Aluminum chloride. Lithium-Ammonia. Lithium diisobutylmethylaluminum hydride. Lithium-Diphenyl. Lithium ethylenediamine. Lithium-Hexamethylphosphoric triamide. Lithium hydride. Lithium triethoxyaluminum hydride. Lithium tri-/-butoxyaluminum hydride. Nickel-aluminum alloy. Pyridine-n-Butyllithium. Sodium amalgam. Sodium-Ammonia. Sodium borohydride. Sodium borohydride-BFs, see DDQ. Sodium dihydrobis-(2-methoxyethoxy) aluminate. Sodium hydrosulflte. Sodium telluride. Stannous chloride. Tin-HBr. Tri-n-butyltin hydride. Trimethyl phosphite, see Dinitrogen tetroxide. 

Sodium borohydride reacts with boron halides to form diborane [19287-45-7] 2 6 more conveniendy handled as the monomer... 

Reductions with diborane have been investigated by Brown and his co-workers. Diborane is an inflammable toxic gas which is available commercially or may be generated by the reaction of sodium borohydride and... 

The nitro substituent is also preserved dunng fluoroester reduction with sodium borohydride [S3] (equation 67) Use of diborane itself allows reduction of nitrodifluoroacetanihde to the amine, Al-nitrodifluoroethylaniline [84] (equation 68)... 

The sodium borohydride solution is added dropwise to the stirred boron trifluoride etherate-diglyme solution resulting in the formation of diborane. The gas is swept into the olefin-TH F solution (held at 20°) by maintaining a slow flow of dry nitrogen through the generator. 

Acetyl-5//-dibenz[/>,/]azepine-10-car bon itrile (17, R = CN) when treated with sodium borohydride undergoes reduction (73 % yield) at the CIO - Cl 1 double bond without reduction of the acetyl or cyano groups.212 However, hydroboration of 5-acetyl-5//-dibenz[/y/]azepine (17, R = H) with diborane in tetrahydrofuran under standard conditions is accompanied by reduction of the acyl function to yield 5-ethyi-10,l l-dihydrodibenz[6,/]azepin-10-ol (18).72... 

H.12 The reaction of boron trifluoride, BF,(g), with sodium borohydride, NaBH4(s), leads to the formation of sodium tetrafluoroborate, NaBF4(s), and diborane gas, B2Hfc(g). The diborane reacts with the oxygen in air, forming boron oxide, B20 j(s), and water. Write the two balanced equations leading to the formation of boron oxide. 

Boron forms a remarkable series of binary compounds with hydrogen—the boranes. These compounds include diborane, B2H6, and more complex compounds such as decaborane, B10H14. Anionic versions of these compounds, the borohydrides, are known the most important is BH4 as sodium borohydride, NaBH4. 

We pointed out that sodium borohydride on a weight basis should be far more efficient than sodium hydroxide and ferrosilicon. Although we had never used it for hydrogen generation, we had no doubt that it would be similar to diborane in reacting readily with water to liberate hydrogen. They asked for a demonstration. 

War research forced us to explore new synthetic routes and we discovered the alkali metal hydride route to diborane. This solved the synthetic problem. At the same time we discovered sodium borohydride and developed simple synthetic methods for its preparation and manufacture. 

An alternative diborane source was used by the checker. Diborane was generated by adding boron trifluoride-ethyl ether to sodium tetrahydroborate (sodium borohydride) in ether. The generator was charged to yield a maximum of 0.6 mol of... 

A boron analog - sodium borohydride - was prepared by reaction of sodium hydride with trimethyl borate [84 or with sodium fluoroborate and hydrogen [55], and gives, on treatment with boron trifluoride or aluminum chloride, borane (diborane) [86. Borane is a strong Lewis acid and forms complexes with many Lewis bases. Some of them, such as complexes with dimethyl sulfide, trimethyl amine and others, are sufficiently stable to have been made commercially available. Some others should be handled with precautions. A spontaneous explosion of a molar solution of borane in tetrahydrofuran stored at less than 15° out of direct sunlight has been reported [87]. 

Opening of a bottle where some particles of lithium aluminum hydride were squeezed between the neck and the stopper caused a fire [68]. Lithium aluminum hydride must not be crushed in a porcelain mortar with a pestle. Fire and even explosion may result from contact of lithium aluminum hydride with small amounts of water or moisture. Sodium bis(2-methoxy-ethoxy)aluminum hydride (Vitride, Red-Al ) delivered in benzene or toluene solutions also may ignite in contact with water. Borane (diborane) ignites in contact with air and is therefore kept in solutions in tetrahydrofuran or in complexes with amines and sulfides. Powdered lithium borohydride may ignite in moist air. Sodium borohydride and sodium cyanoborohydride, on the other hand, are considered safe. ... 

Reduction of aromatic carboxylic acids to alcohols can be achieved by hydrides and complex hydrides, e.g. lithium aluminum hydride 968], sodium aluminum hydride [55] and sodium bis 2-methoxyethoxy)aluminum hydride [544, 969, 970], and with borane (diborane) [976] prepared from sodium borohydride and boron trifluoride etherate [971, 977] or aluminum chloride [755, 975] in diglyme. Sodium borohydride alone does not reduce free carboxylic acids. Anthranilic acid was reduced to the corresponding alcohol by electroreduction in sulfuric acid at 20-30° in 69-78% yield [979],... 

Diborane is prepared by the reaction of sodium borohydride with iodine or boron trifluoride or trichloride in diglyme ... 

Also, sodium borohydride can be made by passing diborane, B2H6, through a solution of sodium methylate, NaOCH3, in methanol ... 

Borazine, B3N3H6, was first prepared by thermolysis of the diborane ammonia adduct [(BH2)(NH3)2] [BH4] . More convenient procedures for the laboratory preparation of this important ring system in multigram quantities involve either (a) the decomposition of ammonia- borane [eqn (9.1)] or (b) the reaction between ammonium sulfate and sodium borohydride [eqn (9.2)]. The latter method provides a convenient and economical synthesis of borazine. 

Sodium borohydride reacts with Lewis acids in nonprotic solvents to yield diborane [19287-45-7], B2H6 (18), which can then be used to generate other useful organoboranes such as amine boranes, alkyl boranes, and boron hydride clusters. 

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