Hydride Sodium borohydride

Hydroxymethylferrocene has been made by condensing ferrocene with N-methylformanilide to give ferrocenecarboxalde-hyde, and reducing the latter with lithium aluminum hydride, sodium borohydride, or formaldehyde and alkali. The present procedure is based on the method of Lindsay and Hauser. A similar procedure has been used to convert gramine methiodide to 3-hydroxymethylindole, and the method could probably be used to prepare other hydroxymethyl aromatic compounds. 

The Meerwein-Ponndorf-Verley procedure has largely been replaced by reduction procedures that use lithium aluminum hydride, sodium borohydride or derivatives thereof. The Meerwein-Ponndorf-Verley reduction however has the advantage to be a mild and selective method, that does not affect carbon-carbon double or triple bonds present in the substrate molecule. 

The tosylhydrazone is prepared from the carbonyl compound and then reduced with lithium aluminium hydride, sodium borohydride or potassium borohydride. In this way D-glucose tosylhydrazone was converted into crystalline 1-deoxyglucitol by reduction with potassium borohydride... 

In the general context of donor/acceptor formulation, the carbonyl derivatives (especially ketones) are utilized as electron acceptors in a wide variety of reactions such as additions with Grignard reagents, alkyl metals, enolates (aldol condensation), hydroxide (Cannizzaro reaction), alkoxides (Meerwein-Pondorff-Verley reduction), thiolates, phenolates, etc. reduction to alcohols with lithium aluminum hydride, sodium borohydride, trialkyltin hydrides, etc. and cyloadditions with electron-rich olefins (Paterno-Buchi reaction), acetylenes, and dienes.46... 

Nonmetallic systems (Chapter 11) are efficient for catalytic reduction and are complementary to the metallic catalytic methods. For example lithium aluminium hydride, sodium borohydride and borane-tetrahydrofuran have been modified with enantiomerically pure ligands161. Among those catalysts, the chirally modified boron complexes have received increased interest. Several ligands, such as amino alcohols[7], phosphino alcohols18 91 and hydroxysulfoximines[10], com-plexed with the borane, have been found to be selective reducing agents. 

Metal hydrides Calcium hydride, lithium aluminum hydride, sodium borohydride... 

The neutralization values were influenced by reduction with strong reducing agents, lithium aluminum hydride, sodium borohydride, and amalgamated zinc plus hydrochloric acid (35, 46). For the most part, the consumption of NajCOj and of NaOEt decreased in equivalent amounts. This is further confirmation of the assumption that lactones of the fluorescein type or of the lactol type are present. The reaction with sodium ethoxide was shown to be no true neutralization, that is, exchange of H+for Na+, at all, but an addition reaction w ith the formation of the sodium salt of a semi-acetal or ketal ... 

Reduction of l,2,4-triazin-3-ones (84) with Raney nickel, zinc and acetic acid, lithium aluminum hydride, sodium borohydride, titanium(III) chloride, p-toluenethiol, hydrogen and a palladium catalyst, or electrochemically, produces 4,5-dihydro-l,2,4-triazin-3-ones (268) (78HC(33)189, p. 246, 80JHC1237), which may be further reduced to 1,4,5,6-tetrahydro-l,2,4-triazin-3-ones (269). l,2,4-Triazin-3-ones (84) with hydriodic acid and phosphorus yielded imidazoles (05LA(339)243). 3-Alkoxy-l,2,4-triazines (126) and sodium borohydride gave the 2,5-dihydro derivatives (270) (80JOC4594). 

Reduction of amides is an important preparative method for the synthesis of primary amines. Reducing agents used for this purpose include lithium aluminum hydride, sodium borohydride, triphenyl-phosphine (Staudinger reduction), and thiols. In the present case it is important to consider the compatibility of the reduction system with the carboxylic and methanesulfonic acid functions. Platinum and palladium arc often used for catalytic reduction. 

In contrast to lithium aluminum hydride, sodium borohydride does not reduce amides. Another possible reagent would be DIB AH. However, in the present case four equivalents of borane-dimethyl sulfide complex was used as a 2M solution in THE The amine was obtained in 94% yield after workup with ethanol. 

One Te-C bond in a diorgano tellurium can be cleaved by alkali metals, organic lithium compounds, sodium hydroxide, lithium aluminum hydride, sodium borohydride, Grignard reagents, tributyltin hydride, sulfuric acid, sodium sulfide, sulfuryl chloride, hydrogen bromide, bromine, or iodine. The Te-C bond can also be broken thermally or through photostimulation. 

REDUCTION, REAGENTS Bis(N-methylpi-perazinyl)aluminum hydride. Borane-Di-methyl sulfide. Borane-Tetrahydrofurane. Borane-Pyridine. n-Butyllithium-Diisobu-tylaluminum hydride. Calcium-Amines. Diisobutylaluminum hydride. 8-Hydroxy-quinolinedihydroboronite. Lithium aluminum hydride. Lithium 9-boratabicy-clo[3.3.1]nonane. Lithium n-butyldiisopro-pylaluminum hydride. Lithium tri-j c-butylborohydride. Lithium triethylborohy-dride. Monochloroalane. Nickel boride. 2-Phenylbenzothiazoline. Potassium 9-(2,3-dimethyl-2-butoxy)-9-boratabicy-clo[3.3.1]nonane. Raney nickel. Sodium bis(2-methoxyethoxy)aluminum hydride. Sodium borohydride. Sodium borohy-dride-Nickel chloride. Sodium borohy-dride-Praeseodymium chloride. So-dium(dimethylamino)borohydride. Sodium hydrogen telluride. Thexyl chloroborane-Dimethyl sulfide. Tri-n-butylphosphine-Diphenyl disulfide. Tri-n-butyltin hydride. Zinc-l,2-Dibromoethane. Zinc borohydride. 

Sodium bis(2-methoxyethoxy)aluminum) hydride. Sodium borohydride-Cerium trichloride. Sodium cyanoborohydride. Sodium dithionite. Sodium hydroxy-... 

Aldehydes and ketones may be reduced to the corresponding primary and secondary alcohols by reagents such as lithium aluminium hydride, sodium borohydride, sodium and ethanol or hydrogen over a platinum catalyst. A ketone is reduced to a methylene group under more vigorous conditions with zinc amalgam and concentrated hydrochloric acid (the Clemmensen reduction) or treatment of the hydrazone with alkali (the Wolff-Kishner reduction)) (Scheme 3.39). 

Reduction of quinazoline to 1,2,3,4-tetrahydroquinazoline requires stronger conditions and can be performed with lithium aluminum hydride, sodium borohydride, sodium cyanoborohydride in the presence of benzyl chloroformate, or sodium amalgam. ... 

When deprotection reactions of the Aloe group with a palladium catalyst and pseudometallic hydrides, namely tributyltin hydride, sodium borohydride, or phenylsUane, are performed in the presence of an acylating agent, the deprotected amino group is directly obtained in its acylated form.P This tandem deprotection-acylation reaction is believed to involve a concerted decarboxylative condensation of the initially formed pseudometallic carbamate with the acylating agent, as represented in Scheme 8 in the case of hydrostannolysis.t ... 

Considering the extreme reactivity of most hydrides (such as sodium hydride and lithium aluminum hydride) toward water, sodium borohydride is somewhat surprisingly sold as a stabilized aqueous solution 14 molar in sodium hydroxide containing 12% sodium borohydride. Unlike lithium aluminum hydride, sodium borohydride is insoluble in ether and soluble in methanol and ethanol. 

Oxycellulose and phenylhydrazine gave a yellow compound, which formed a diphenylformazan, showing that the oxycellulose had reacted in one of the two possible hemiacetal forms. Aminophenols and oxycellulose gave derivatives which coupled with diazonium compounds, enabling chemically colored fibers to be prepared. Reduction of oxycellulose oxime with lithium aluminum hydride, sodium borohydride, or sodium amalgam gave an amino-oxycellulose (109) in which up to 25 % of the oxime groups had been reduced. ... 

The reactions are commonly initiated with AIBN at ca. 80 °C in a solvent such as benzene or toluene, but alkyl halides have also been reduced at -60 °C with tributyltin hydride under sonication conditions.133-134 Some reductions of halides have been carried out by generating the tin hydride in situ from a molar equivalent of the reducing agent [lithium aluminium hydride, sodium borohydride, or poly(methylhydrosiloxane)] and a catalytic amount of organotin hydride, halide, or oxide. Reduction of halides has also been carried out under aqueous conditions, using 4,4 -azobis(4-cyanovaleric acid) (ACVA) as a water-soluble radical initiator.60... 

Reduction of the halides with a metal hydride such as lithium aluminium hydride, sodium borohydride, or poly(methylhydrosiloxane) gives the corresponding organotin hydrides These have an important place in organic synthesis for the reduction of halides to hydrides (hydrostannolysis) and the addition to alkenes and alkynes (hydrostannation), by radical chain reactions. Further reactions may intervene between the pairs of reactions shown in Equations (1.1.3) and (1.1.4), and (1.1.4) and (1.1.5), and these reactions are particularly useful for inducing ring-closure reactions. 

Cyclopropenylium ions 1 were converted into the corresponding cyclopropenes 2 by the addition of hydride ion derived from various hydride sources, such as lithium aluminum hydride,sodium borohydride, borane-amine complex, triethylsilane, and tributyl-tin hydride. Particularly in the case of borohydride reduction of the diphenylcyclo-propenylium ion, the order of reagent addition was quite important. The slow addition of an acetonitrile solution of the cyclopropenylium salt into a solution of the borohydride gave the cyclopropene derivative,whereas the inverse order of addition resulted in quantitative formation of 1,2,4,5-tetraphenylbenzene (see Section 2.1.2.3.), No such precaution of the inverse addition was required in the case of borane-amine reduction of the l-chloro-2,3-diphenyl-cyclopropenylium ion. ... 

The presence of the epoxide moiety at C-3 and C-4 in excelsine explained the interesting chemical reactions observed earlier. On treatment with acetic anhydride and p-toluenesulfonic acid, excelsine yielded a triacetate derivative, while treatment with acetyl chloride afforded a tetraacetate derivative. On reduction with Raney nickel in methanolic base, excelsine yielded lapaconidine (92), but was inert toward other reducing agents, e.g., lithium aluminum hydride, sodium borohydride, and Adams catalyst. Treatment of excelsine with boiling aqueous hydrochloric acid yielded an epimeric mixture of chlorohydrins with molecular formula C22H34NO6CI. These epimers were hydrolyzed to the crystalline compound C22H33NO6 when treated with aqueous sulfuric acid. This compound formed a tetraacetate derivative for which structure 105 was proposed on the basis of spectral data. 

INORGANIC PREPARATION OF OTHER HYDRIDES. Sodium hydride is one of the cheapest raw materials for the production of other hydrides. Sodium borohydride is prepared commercially by the reaction ... 

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