Boron triethyl

TEB (Triethylborane, Triethylborine or Boron Triethyl). (C2HS)3B mw 98.13 colorl pyrophoric liq mp —93° bp 95° d 0.6961g/cc at 23° RI 1.3971. Miscible with most org solvents immiscible with w. Prepn is by dropwise addn of an n-butyl eth soln of BF3 to a soln of ethyl Mg bromide in n-butyl eth. Upon completion of the reaction the prod is distld off at 95° under N2. Also, by the reaction of triethyl Al with B halide, or diborane with ethylene. TEB has a flash pt of 0° a Qc of 20000BTU/lb and, according to Sax (Ref 4), a high vap toxicity... 

The first organic compound of boron was isolated by Frankland in 1862, by the interaction of zinc methyl and triethyl borate. This method and the use of zinc alkyls with boron trichloride was continued until the discovery of the Grignard reagent. In 1900 boron tri-methyl was prepared by the action of magnesium methyl iodide on trimethyl borate, and in 1921 a number of boron trialkyls were obtained by the interaction of magnesium alkyl halides and boron trifluoride. Of the derivatives of the type RgB, boron trimethyl is a gas, spontaneously inflammable in air boron triethyl, a spontaneously inflammable liquid whilst the higher members of the series are liquids, readily oxidised when exposed to air. The metl yL fpd ethyl derivatives combine with ammonia to foriii IliS type I BOH only... 

Boron triethyl —This is prepared by the action of zinc ethyl on the triethyl ester of boric add, and also by the interaction of zinc ethyl and boron trichloride. Frankland described it as a fuming liquid, spontaneously inflammable in air. It melts at 92-0 C., and boils at 95 C. density at 23 0-0031 vapour pressure at 0 C., 12 5 mm. It... 

The diethyl ester, Et.B(OEt)2, is a liquid, boiling with decomposition at 125° C, and is decomposed by w ater like the monoethyl derivative. It is formed when boron triethyl is oxidised in air and then in oxygen, or when dry oxygen acts upon the ethyl ester of diethyl boric acid. 

Beilstein Handbook Reference) Borane, triethyl- Boron ethyl Boron triethyl BRN 1731462 EINECS 202-620-9 HSDB 897 Triethylborane Triethylborine Triethylboron. Used as an initiator of radical reactions. Liquid mp = -93° bp = 95° d = 0.700 ... 

CAS 97-94-9 EINECS/ELINCS 202-620-9 Synonyms Boron triethyl TEB Triethylborine... 

Laubengayer, A.W., Ferguson, R.P., Newkirk, A.E., 1941. The densities, surface tensions and parachors of diborane, boron triethyl and boron tribromide. The atomic parachor of boron. J. Am. Chem. Soc. 63, 559-561. 

MOCVD has also been used with triethyl boron as the boron source in a hydrogen and argon atmosphere ]... 

These oxazolidinones can be acylated and converted to the lithium, boron, tin, or titanium enolates by the same methods applicable to ketones and esters. For example, when they are converted to boron enolates using di-n-butylboron triflate and triethyl-amine, the enolates are the Z-stereoisomers.125... 

Benzaldehyde diethyl acetal (5.94 g, 32.9 mmol) and triethyl phosphite (5.45 g, 32.9 mmol) were dissolved in dichloromethane (60 ml) under an inert atmosphere and cooled to -20°C. Boron trifluoride etherate (3.57 g, 35.2 mmol) was then added dropwise. The resulting mixture was allowed to return to ambient temperature over an 18-h... 

Fuostifoline (47), a furo[3,2-a]carbazole, was isolated from Murraya euchrestifolia. Timdri s total synthesis of 47 commenced with alkylation of bromocresol 43 with bromoacetaldehyde diethyl acetal and P4Oio-promoted cyclization to furnish 5-bromo-7-methylbenzofuran (44) [47]. The Suzuki coupling of boronic acid 45, derived from 44, with o-bromonitrobenzene yielded biaryl 46. Nitrene generation, achieved via deoxygenation of nitro compound 46 using triethyl phosphite, was followed by cyclization to fuostifoline (47). 

Often Lewis acids are added to the system as a cocatalyst. It could be envisaged that Lewis acids enhance the cationic nature of the nickel species and increase the rate of reductive elimination. Indeed, the Lewis acidity mainly determines the activity of the catalyst. It may influence the regioselectivity of the catalyst in such a way as to give more linear product, but this seems not to be the case. Lewis acids are particularly important in the addition of the second molecule of HCN to molecules 2 and 4. Stoichiometrically, Lewis acids (boron compounds, triethyl aluminium) accelerate reductive elimination of RCN (R=CH2Si(CH3)3) from palladium complexes P2Pd(R)(CN) (P2= e g. dppp) [7], This may involve complexation of the Lewis acid to the cyanide anion, thus decreasing the electron density at the metal and accelerating the reductive elimination. 

Using 10% of DTBB as electron carrier, 2,5-disubstituted chlorocyclopentanes 6 were lithiated, the corresponding organolithium intermediates having being employed for the preparation of boronic esters 7, after reaction with triethyl borate and the corresponding 1,3-diol (Scheme 4). ... 

Several catalysts and initiator systems have been tested for the polymerization of GlcAnBzl3, including the following Lewis acids boron trifluoride and its etherate, phosphorus pentafluoride, titanium tetrachloride, and antimony pentachloride and pentafluoride. Several cationic initiators have also been used, including (triphenylmethyl) antimony hexachloride, 2,3,4,6-tetra-O-acetyl-D-glucopyranosyl hexa-fluorophosphate, acetyl hexafluorophosphate, pentamethylbenzyl hexa-fluorophosphate (most of which were generated in situ), and triethyl-... 

Rozenberg et al. (24) have also studied the kinetics of polymerization of THF initiated by triethyl oxonium tetrafluoroborate. They generated their catalyst in situ from epichlorohydrin and the boron trifluoride-ether cofnplex and carried out their polymerizations in bulk and in... 

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