Reaction Of Trialkylboranes Research Articles

ChemInform Abstract: Reaction of Trialkylboranes with Sodium Diethyldihydroaluminate in the Presence of 1,4-Diazabicyclo(2.2.2)octane. A Convenient, General Method for Preparation of Sodium Trialkylborohydrides.

Abstract Trialkylboranes in tetrahydrofuran (THF) or diethyl ether (EE) solutions, including those with exceptionally large steric requirements, react readily with toluene solutions of sodium diethyldihydroaluminate in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield the corresponding sodium trialkylborohydrides and diethylaluminum hydride. The diethylaluminum hydride precipitates from solution as its DABCO adduct, with the use of EE as solvent facilitating the separation. This reaction constitutes a convenient, general method for preparing sodium trialkylborohydrides.

ChemInform Abstract: Reaction of Trialkylboranes with Nitrones: A Novel Route to α‐ Alkylated Hydroxylamines.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reaction of Trialkylboranes with Nitrones: A Novel Route to .alpha.-Alkylated Hydroxylamines

Reaction of Trialkylboranes with Nitrones: A Novel Route to .alpha.-Alkylated Hydroxylamines

Reaction of trialkylboranes with sodium diethyldihydroaluminate in the presence of 1,4-diazabicyclo[2.2.2]octane. a convenient, general method for preparation of sodium trialkylborohydrides

Trialkylboranes in tetrahydrofuran (THF) or diethyl ether (EE) solutions, including those with exceptionally large steric requirements, react readily with toluene solutions of sodium diethyldihydroaluminate in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield the corresponding sodium trialkylborohydrides and diethylaluminum hydride. The diethylaluminum hydride precipitates from solution as its DABCO adduct, with the use of EE as solvent facilitating the separation. This reaction constitutes a convenient, general method for preparing sodium trialkylborohydrides.

Cyclization reactions of ?-tosyloxy-1-alkynyl- and ?-tosyloxy-1-alkenylborates and their ?-halo analogues

The reaction of trialkylboranes with ω-tosyloxy-1-lithio-1-alkynes can induce transfer of an alkyl group from the boron atom to the alkynyl carbon atom with concomitant formation of four- through six-membered carbocycles via intramolecular displacement of the ω-tosyloxy group. The stereoselectivity of the reaction, however, is low (anti/syn≃1.6–1.7). The corresponding reaction of ω-halo- or ω-tosyloxy-1-alkenylborates also gives exocyclic alkenes via 1,2-migration-cyclization followed by dehydroboration. In the cases of cyclopropanation, cyclopropylcarbinyl-to-homopropargyl rearrangement rather than dehydroboration takes place. Diphenylzirconocene reacts similarly with 6-lithio-5-hexynyl tosylate to give phenylmethylenecyclopentane in 45% yield. On the other hand, attempts to induce a similar migration with phenyl derivatives of Y, V, Cr, and Mn have led to < 5–10% yields of the same cyclization product.

Substituted C3BN2 Heterocycles from Trialkylboranes and Nitriles

The reaction of trialkylboranes, e. g. triethylborane (Et3B), tripropylborane (Pr3B), or 9‐alkyl‐9‐borabicyclo[3.3.1]nonane [alkyl‐BBN; alkyl=Et, 1‐methylpropyl, 1‐methybutyl/1‐ethylpropyl], with either aceto‐, propio‐, butyro‐, pivalo‐, and benzonitrile gives, depending on the reaction conditions used or the nitrile employed, either the substituted diazoniadibora‐tetidines (1 a—c), products of partial hydroboration, or by condensation of two or three nitrile molecules, with or without a concomitant hydroboration, the C3BN2 heterocycles 2a—c, 8a/b, 9a—d, and 10a/b (X‐ray structure analyses of 2a and 10b).

ChemInform Abstract: Reaction of Trialkylboranes with Sodium Diethyldihydroaluminate in the Presence of 1,4‐Diazabicyclo(2.2.2)octane: A Convenient, General Method for Preparation of Sodium Trialkylhydroborates.

AbstractThe boranes (I) react with sodium diethyldihydroaluminate (II) in the presence of 1,4‐diazabicyclo(2.2.2)octane (DABCO) to produce the sodium tri(cyclo)alkylhydroborates (III).

Reaction of trialkylboranes with alkylamines: synthesis of dialkylamines

Reaction of trialkylboranes with alkylamines: synthesis of dialkylamines

Reaction of trialkylboranes with sodium diethyldihydroaluminate in the presence of 1,4-diazabicyclo[2.2.2]octane: a convenient, general method for preparation of sodium trialkylhydroborates

Trialkylboranes in tetrahydrofuran solution, even those with exceptionally large steric requirements, react readily with toluene solutions of sodium diethyldihydroaluminate in the presece of 1,4-diazabicyclo[2.2.2]octane, resulting in a convenient and general preparation of sodium trialkylhydroborates.

ChemInform Abstract: Organoboranes for Synthesis. Part 10. The Base‐Induced Reaction of Bromine with Organoboranes. A Convenient Procedure for the Conversion of Alkenes into Alkyl Bromides via Hydroboration.

AbstractThe reaction of trialkylboranes with bromine is greatly accelerated by a base.

Organoboranes for synthesis. 10. 1 the base-induced reaction of bromine with organoboranes. A convenient procedure for the conversion of alkenes into alkyl bromides via hydroboration

The reaction of trialkylboranes with bromine is greatly accelerated by base. Bromination in the presence of sodium hydroxide provides alkyl bromide along with a large amount of the corresponding alcohol. The use of sodium methoxide as a base eliminates this undesirable sidereaction and provides an improved yield of alkyl bromide. Consequently, hydroboration, followed by bromination in the presence of sodium methoxide, provides a convenient new procedure for the conversion of alkenes into alkyl bromides. The organoboranes, obtained via hydroboration of terminal alkenes, react with the utilization of all three alkyl groups attached to boron, providing nearly quantitative yields of alkyl bromides. This procedure also accommodates common organic functional groups, as demonstrated by the preparation of methyl 11-bromoundecanoate and 11-bromoundecyl acetate from the corresponding functionally substituted alkenes. Under these conditions, secondary and bulky primary alkyl groups react more sluggishly. However, a procedure involving simultaneous addition of bromine and methanolic sodium methoxide provides improved results for such derivatives. Surprisingly, the base-induced bromination of tri-exo-norbomylborane results in an inversion of configuration at the reaction center to give predominantly endo-2-bromonorbomane. A mechanism is proposed to account for this remarkable inversion.

Organoboranes for synthesis : Reaction of organoboranes with representative organic azides. A general stereospecific synthesis of secondary amines and N-substituted aziridines

Reaction of trialkylboranes with organic azides in refluxing xylene, followed by hydrolysis, leads to good yields of secondary amines. This reaction is highly dependent on the steric effects around both boron and the azide moiety. The reaction becomes much slower when the steric bulk of one of the reagents is increased and fails when both are hindered. The dialkylchloroboranes are more reactive than trialkylboranes and provide better yields of the desired secondary amines with a11 azides tested. The alkyldichloroboranes react with organic azides at temperatures between room temperature and 60°C and produce excellent yields of secondary amines. Furthermore, the stereochemistry of the original carbon-boron bond is retained. The mechanism of these reactions is discussed and the reaction applied to the synthesis of N-alkyl- and N-arylaziridines.

The Reaction of Trialkylboranes with Allyl Phenyl Ether. Syntheses of 1-Alkenes and 1,5-Alkadienes

Abstract In the organoborane chemistry, the homologation reaction is one of the useful methods for the synthesis of organoboranes not available via hydroboration.1) The allylic boranes are known to be highly reactive and exhibit specific behaviors,2) but with few exceptions,3) these are difficult to be prepared directly by the hydroboration reaction.5) Previously, we reported that in the reaction of the dianion of phenoxyacetic acid with organoborane, the phenoxy group acts as a good leaving group.6) This result suggested us a new homologation reaction converting a saturated organoborane to a allylic borane (1) by the treatment with the carbanion of allyl phenyl ether. Here we wish to report the synthesis of 1-alkenes (II) three-carbon-homologated from starting alkenes7) and the regioselective synthesis of 1,5-dienes (III) using allylic borane intermediates (1) (eq. 1).

Addition compounds of alkali metal hydrides. 14. The reaction of trialkylboranes with lithium trialkylborohydrides

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAddition compounds of alkali metal hydrides. 14. The reaction of trialkylboranes with lithium trialkylborohydridesHerbert C. Brown, Albert Khuri, and S. KrishnamurthyCite this: J. Am. Chem. Soc. 1977, 99, 19, 6237–6242Publication Date (Print):September 1, 1977Publication History Published online1 May 2002Published inissue 1 September 1977https://doi.org/10.1021/ja00461a010RIGHTS & PERMISSIONSArticle Views181Altmetric-Citations23LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (594 KB) Get e-Alerts Get e-Alerts

The preparation of trialkylvinylborates and their reactions with oxiranes and with iodine. A facile synthesis of 1,4-alkanediols and 1-alkenes

Reaction of trialkylboranes with vinyllithium gives non-isolable lithium trialkylvinylborates which react with oxirane and methyloxirane affording 1,4- and 2,5-alkanediols, respectively. Treatment of trialkylboranes with vinylmagnesium bromide produces bromomagnesium trialkylvinylborates which analogously afford alkanediols. Successive treatment of the borates with aqueous alkali and iodine provides 1-alkenes.

The reaction of trialkylboranes with α-methoxyvinyllithium a novel route to dialkylmethylcarbinols

The reaction of trialkylboranes with α-methoxyvinyllithium a novel route to dialkylmethylcarbinols

Reaction of trialkylboranes with 2-bromo-6-lithiopyridine: Stereospecific alkylative cleavage of pyridine ring

Reaction of 2-bromo-6-lithiopyridine with trialkylboranes affords 5-alkyl-5-dialkylboryl-2-( Z), 4( E)- pentadienenitriles by stereospecific alkylative cleavage of the pyridine ring. These intermediary vinylboranes are versatile reagents for the preparation of 5-alkyl-2( Z), 4( E)-pentadienenitriles, 5,5-dialkyl-4-pentenenitriles and 5,5-dialkyl-2,4-pentadienenitriles.

Preparation of secondary alcohols by reaction of trialkylboranes with bis(phenylthio)methyl-lithium

Preparation of secondary alcohols by reaction of trialkylboranes with bis(phenylthio)methyl-lithium

ChemInform Abstract: A NEW ROUTE TO DIALKYL SELENIDE FROM OLEFIN VIA HYDROBORATION

AbstractTrialkylborane, dargestellt aus den Olefinen (I) mit BH3, reagieren mit SeO2 in wäßriger Lösung zu den.

A NEW ROUTE TO DIALKYL SELENIDE FROM OLEFIN VIA HYDROBORATION

Abstract The reaction of trialkylboranes, prepared from olefin via hydroboration, with selenium dioxide was studied. In the aqueous selenium dioxide solution, trialkylboranes give the mixtures of dialkyl selenide and dialkyl diselenide, whereas in the suspension of selenium dioxide in tetrahydrofuran, trialkylboranes give dialkyl selenides selectively under the condition where the reaction time and the amount of selenium dioxide are controlled.