Borohydrides reacting with

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

Lithium borohydride reacted with aluminum chloride to produce aluminum borohydride (7). 

Tetraalkylammonium borohydrides react with elemental selenium and tellurium to form the symmetrical dialkyl selenides and tellurides [44]. Diphenyl selenide yields the alkyl phenyl selenides. 

Quaternary ammonium borohydrides react with diborane to produce the corresponding ammonium diboronoheptahydrides, which behave both as borohydrides and as diborane [3]. 

Lithium aluminum hydride and sodium borohydride react with alcohols and form alkoxyaluminohydrides and alkoxyborohydrides most widely used... 

Other reagents used for reduction are boranes and complex borohydrides. Lithium borohydride whose reducing power lies between that of lithium aluminum hydride and that of sodium borohydride reacts with esters sluggishly and requires refluxing for several hours in ether or tetrahydrofuran (in which it is more soluble) [750]. The reduction of esters with lithium borohydride is strongly catalyzed by boranes such as B-methoxy-9-bora-bicyclo[3.3.1]nonane and some other complex lithium borohydrides such as lithium triethylborohydride and lithium 9-borabicyclo[3.3.1]nonane. Addition of 10mol% of such hydrides shortens the time necessary for complete reduction of esters in ether or tetrahydrofuran from 8 hours to 0.5-1 hour [1060],... 

Lithium borohydride reacts with water with liberation of hydrogen ... 

Borohydride reacts with vinylidene complexes to give a-vinyls. Examples include Fe (=C=CH2)(CO)(PPh3)Cp [9] and Fe(=C=CMePh)(dppm)Cp [283]. A carbyne complex is formed by addition of K[BHBu%] to MoBr(=C=CPh)(PEt3) P(OMe)3 Cp [237]. 

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. 

Sodium arenetellurolates, prepared by reduction of diaryl ditelluriums with sodium borohydride, reacted with 1,4-dichlorobutane7, 1,4-dibromobutane7, and 1,5-dibromo-pentane8 forming aryl tetra- or pentamethylene telluronium halides. 

Sodium borohydride is one of the weakest hydride donors available. The feet that it can be used in water is evidence of this as more powerful hydride donors such as lithium aluminium hydride, LiAlI-fe, react violently with water. Sodium borohydride reacts with both aldehydes and ketones, though the reaction with ketones is slower for example, benzaldehyde is reduced about 400 times faster than acetophenone in isopropanol. 

In recent years transition metal fiuorides have attained more and more attention as effective dopant precursors for complex hydrides [66, 67]. It is well known that aluminum hydrides, as well as borohydrides, react with fluorine to form fluorides [68]. In addition, many fluorides and hydrides are isotypic. One example is... 

Beryllium borohydride reacts with triethylamine to give the compound Be(BH4)2N(GH3)3. The structure of this compound is not fully understood, but may be represented by... 

Lithium alkanetellurolates, prepared from tellurium and an alkyl lithium compound or dialkyl ditellurium derivatives and hthium, and sodium arenetellurolates, obtained from diaryl ditellurium compounds and sodium borohydride ", reacted with triorganosilyl, -germyl, -stannyl, and -plumbyl chlorides to produce, for instance, organo triorganosilyl tellurium compounds. 

Prelab Exercise Calculate the volume of hydrogen gas generated when 3 mL of 1 M sodium borohydride reacts with concentrated hydrochloric acid. Write a balanced equation for the reaction of sodium borohydride with platinum chloride. Calculate the volume of hydrogen that can be liberated by reacting 1 g of zinc with acid. 

A suspension of sodium borohydride is essentially inert to chiral amino alcohols and is unable to reduce ketoxime O-alkyl ethers. On the other hand, when combined with a Lewis acid (e.g., ZrCb), sodium borohydride reacts with chiral amino alcohols with evolution of hydrogen to form a chiral borohydride reagent. This chirally modified borohydride has the ability to reduce the C —N double bond of ketone O-alkyl ethers to give chiral primary amines in 78-95% yield with 43-90% ee34. 

Sodium borohydride reacts with CgFnSChF in ether and alcohol at 16° to give pcrfluoro-n-octanesulfinate ion, CgFI7S02. The /S-benzylthiuronium salt of this ion melts at 130° (36). 

CHEMICAL PROPERTIES thermally unstable water reactive hydrolyzes in water to hydrogen and boric acid reacts with ammonia to form diborane diammoniate reacts slowly with bromine to form boron bromides reacts with hydrocarbons or organoboron compounds to give alkyl- or aryl-boron compounds reacts with metal alkyls to form metal borohydrides reacts with strong electron pair donors to form borane addition compounds FP (-90°C, -130°F) LFL/UFL (0.9%, 98%) AT (40-50°C, 104-122°F) HF (35.6 kJ/mol gas at 25°C). 

In Chapter 19 (Section 19.2), lithium aluminum hydride and sodium borohydride reacted with ketones or aldehydes via acyl addition to reduce the carbonyl to the corresponding alcohol. This reaction is complicated by the presence of a conjugating n-bond. When cyclohexenone reacts with LiAlH4, the product is a mixture of cyclohexenol (66) and cyclohexanol (67). Cyclohexenol results from 1,2 addition of the hydride, but 67 results from 1,4 addition and 1,2 addition. 

Derivatization. Components with active groups such as hydroxyl, amine, carboxyl, and olefin can be identified by a combination of chemical reactions and GC. For example, the sample can be shaken with bromine water and then chromatographed. Peaks due to olefinic compounds will have disappeared. Similarly, potassium borohydride reacts with carbonyl compounds to form the corresponding alcohols. Comparison of before and after chromatograms will show that one or more peaks have vanished whereas others have appeared somewhere else on the chromatogram. Compounds are often derivatized to make them more volatile or less polar (e.g., by silylation, acetylation, methy-lation) and consequently suitable for analysis by GC. 

R3PbOCH3 + 3(BH3>2 4R3PbBH4+2HB(OCH3>2 These trialkyl-lead borohydrides react with methanol to release trialkyl-lead hydrides, and decompose at about — 30° to hexa-alkyldileads i. 

Both aluminum hydride and borohydride react with protic solvents such as water and ethanol. Lithium aluminum hydride reacts violently with water to form hydrogen gas, which may burn explosively because of the heat generated in the reaction. Therefore, lithium aluminum hydride can only be used in aprotic solvents such as diethyl ether. 

Because neither lithium aluminum hydride nor sodium borohydride reacts with alkenes or alkynes, these reagents selectively reduce a carbonyl group in compounds with carbon—carbon multiple bonds. 

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