B2H6

NaBH4. See borohydrides. Prepared NaOMe plus B2H6. Used in organic reduc-... 

The structure of diborane B2H6 is considered later (p. 145). Here we may note that "BHj and "AlHj will be acceptor molecules since there are only six valency electrons around the B or A1 atom and a vacant orbital exists. Both in fact can accept the electron pair from a hydride ion thus ... 

Borane (BH3) does not exist as such under normal condi tions of temperature and at mospheric pressure Two molecules of BH3 combine to give diborane (B2H6) which IS the more stable form... 

NaBH4 + 4(C2H5)2-BF3 —>digiyme 2 B2H6 + 3 NaBF4 + 4 (C2H5 )2O... 

Explosions have been reported on distillation of compounds containing a tet-rahydropyranyl ether after a reaction with B2H6/H202-0H and with 40% CH3CO3H ... 

Run Initial pressure B2H6 (torr) M 2C0 Initial rate x 10 (torr/sec)... 

With this as introduction, let us now look at the individual steps in more detail for the case of hydroboration-oxidation of 1-decene. A boron hydride that is often used is dibomne (B2H6). Diborane adds to 1-decene to give tridecylborane according to the balanced equation ... 

Diborane occupies a special place because all the other boranes can be prepared from it (directly or indirectly) it is also one of the most studied and synthetically useful reagents in the whole of chemistry.B2H6 gas can most conveniently be prepared in small quantities by the reaction of I2 on NaBH4 in diglyme [(MeOCH2CH2)20], or by the reaction of a solid tetrahydroborate with an anhydrous acid ... 

When B2H6 is to be used as a reaction intermediate without the need for isolation or purification, the best procedure is to add Et20Bp3 to NaBH4 in a poly ether such as diglyme ... 

Some 200 tonnes per annum of B2H6 is produced commercially, worldwide. Care should be taken in all these reactions because B2H6 is spontaneously flammable its heat of combustion (—A//°) is higher per unit weight of fuel than for any other substance except... 

Careful control of temperature, pressure and reaction time enables the yield of the various intermediate boranes to be optimized. Eor example, B4H10 is best prepared by storing B2H6 under pressure at 25° for 10 days this gives a 15% yield and quantitative conversion according to the... 

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