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Borane, with

Diborane or aUcylboranes are used for reduaion of alkenes and alkynes via hydrobora-tion (see pp. 37f., 47f., 130f.) followed by hydrolysis of the borane with acetic acid (H.C. Brown, 1975). [Pg.96]

Reactions of Boranes with Lewis Bases. Boranes that contain a BH2 moiety, eg, B2H, B H q, hexaborane(12) [28375-94-2] ... [Pg.235]

In most cases the prolonged treatment of a closo carborane or borane with strong base results in the removal of a single-boron vertex to yield a nido cluster, inert to further degradation. This principle is exploited in the polyhedral contraction and subrogation synthetic strategies. In the prototypical case. [Pg.246]

A more convenient high-yield synthesis of Bi2Hi2 is by the direct reaction of amine-boranes with BiqHu in the absence of solvents ... [Pg.163]

By reaction of borane with two equivalents of a-pinene 15, the chiral hydroboration reagent diisopinocampheylborane 16 (Ipc2BH) is formed ... [Pg.171]

Enantioselective reduction is not possible for aldehydes, since the products are primary alcohols in which the reduced carbon is not chiral, but deuterated aldehydes RCDO give a chiral product, and these have been reduced enantioselectively with B-(3-pinanyl)-9-borabicyclo[3.3.1]nonane (Alpine-Borane) with almost complete optical purity. ... [Pg.1201]

Secondary amines are formed by reaction of trisubstituted boranes with alkyl or aryl azides. The most efficient borane intermediates are monoalkyldichloroboranes, which are generated by reaction of an alkene with BHCl2 Et20.190 The entire sequence of steps and the mechanism of the final stages are summarized by the equation below. [Pg.346]

Alkoxy groups can be displaced from boron by alkyl- or aryllithium reagents. The reaction of diisopropoxy boranes with an organolithium reagent, for example, provides good yields of unsymmetrically disubstituted isopropoxyboranes.3... [Pg.785]

A similar situation obtains in a series of para-substituted tribenzylbor-anes (48) bearing X = H, F, Me, and MeO groups47 the UV spectra of 48 exhibit a CT band of medium intensity in the region of 240-285 nm. Such an assignment is supported by the existence of a linear correlation of the CT transition energies of the boranes with the ionization potentials of Ph—X (Eq. 16). [Pg.369]

Diazadiphosphacyclooctane (51) interacts with only two molecules of borane with participation of the phosphorus atoms [Eq. (50)]. The number of borane molecules added is likely to be determined by the conformation of the eight-membered ring, which exists in a distorted boat-boat form similar to that of the analogous sulfide. [Pg.80]

Preparation of phenyl (P-carbomethoxyethyl) phosphine-borane — Reaction of a primary phosphine-borane with an unsaturated ester... [Pg.9]

Reaction of a primary phosphine-borane with an unsaturated ester443... [Pg.83]

Due to difficulties in separating (VII) from the IiCl byproduct, it was found to be advantageous to prepare (VII) by the reaction of a tris(imino)borane with trifluoroborane-etherate as illustrated in Eq. (26). [Pg.49]

The reaction of tris(organothio)boranes with nitriles leads to B—S substituted iminoboranes. 1,2-addition of tris(methylthio)borane or tris(phenylthio) borane to trichloroacetonitrile yields the monomeric products (XIV) or (XV)32). [Pg.55]

Reactions of tris(organothio)boranes with a-halogenated nitriles are very slow (c.f. (II)). Analogous reactions of tris(organothio)boranes with acetonitrile could not be accomplished. [Pg.55]

Boranes have opened the door to asymmetric reduction of carbonyl compounds. The first attempt at modifying borane with a chiral ligand was reported by Fiaud and Kagan,75 who used amphetamine borane and desoxyephedrine borane to reduce acetophenone. The ee of the 1-phenyl ethanol obtained was quite low (<5%). A more successful borane-derived reagent, oxazaborolidine, was introduced by Hirao et al.76 in 1981 and was further improved by Itsuno and Corey.77 Today, this system can provide high stereoselectivity in the asymmetric reduction of carbonyl compounds, including alkyl ketones. [Pg.367]

Li and Yue observed an ethyl transmetalation during the Suzuki coupling of diethyl (3-pyridyl)borane and 3-bromoquinoxaline 44 [35]. In the presence of a strong base (NaOH), the Suzuki reaction of diethyl (3-pyridyl)borane with 3-bromo-6,7-dichloroquinoxalin-2-ylamine (44) proceeded to give 52% of the 3-pyridylquinoxaline 45 accompanied by 21% of 3-ethylquinoxaline 46. [Pg.192]

The reaction of borane with hydride-starting material [(7/s-C5Me5)FcI I2]2 has been explored, and results in the metastable ((r/ -GsMc3)Fc)B4I f 1 284, which reacts further with Co2(CO)8 to give stable (b -CsMeslFe) Co(CO)3 B4H8 285.172... [Pg.163]

Catechol allenylboranes have also been used to synthesize homopropargylic alcohols [25], These reagents are prepared by hydroboration of an enyne with catechol-borane in the presence of a Pd(0) catalyst possessing monodentate phosphine ligands. Dienylboranes were formed as minor products. Optimum results were obtained by treatment of the catecholborane with molar equivalents of triphenylpho-sphine and the palladium catalyst. Although several allenylboranes were prepared, only the dimethyl reagent was further examined. Treatment of that borane with benzaldehyde afforded the homopropargylic alcohol in 62% yield (Eq. 9.21). [Pg.515]

The doso-carboranes with a C2 B3 skeleton are of particular interest because their structure and bonding have been described as classical and non-classical. Koster et al. [49] reported the preparation of pentaalkyl-1,5-dicarba-doso-pentaboranes by hydroboration of dialkyl(l-alkynyl)boranes with tetraalkyl-diboranes(6) (R2BH)2. By using a large excess of (Et2BH)2 as a hydride bath the route to pentaethyl-1,5 -d ic ar ba- doso-pe n tabo ra n e(5) was found to proceed via the 1-carba-aradwo-pentaborane(lO) [50] (see also Section 3.2.2.4 [33]). [Pg.285]

In the following section, we give a survey of the known types of heteroboranes in question and discuss the structures in terms of the Wade-Williams rules. Readers, who are interested in the synthesis of heteroatom clusters, in their skeletal transformations, or in reactions at the ligand sphere, are referred to the cited literature. conjuncto- Boranes with heteroatoms in the skeleton are not considered in this brief discussion. [Pg.323]

In the late 1960s, methods were developed for the synthesis of alkylated ketones, esters, and amides via the reaction of trialkyl-boranes with a-diazocarbonyl compounds (50,51), halogen-substituted enolates (52), and sulfur ylids (53) (eqs. [33]-[35]). Only one study has addressed the stereochemical aspects of these reactions in detail. Masamune (54) reported that diazoketones 56 (Ri = CH3, CH2Ph, Ph), upon reaction with tributylborane, afford almost exclusively the ( )-enolate, in qualitative agreement with an earlier report by Pasto (55). It was also found that E) - (Z)-enolate isomerization could be accomplished with a catalytic amount of lithium phenoxide (CgHg, 16 hr, 22°C) (54). [Pg.39]

Bidentate boranes with an o-phenylene backbone constitute some of the simplest examples of polydentate Lewis acids with rigid backbones. They can be prepared by the reaction of boron halides with a 1,2-dimetallated benzene derivative. Thus, the reaction of 1,2-bis(chloromercurio)benzene (5) with boron trichloride affords 1,2-bis(dichloroboryl)benzene (6, Scheme 3). ... [Pg.62]

An additional protocol involves the reaction of vinyl boranes with diorganyl ditellurides. [Pg.94]

Addition of alane and borane to alkenes affords a host of alkylated alanes and boranes with various reducing properties (and sometimes bizarre names) diisobutylalane (Dibal-H ) [104], 9-borabicyclo[3.3.1]nonane (9-BBN) (prepared from borane and 1,5-cyclooctadiene) [705], mono- [106,107] and diiso-pinocampheylborane (B-di-3-pinanylborane) (both prepared from borane and optically active a-pinene) [108], isopinocampheyl-9-borabicyclo[3.3.1 Jnonane alias B-3-pinanyl-9-borabicyclo[3.3.1]nonane (3-pinanyl-9-BBN) (prepared from 9-borabicyclo [3.3.1]nonane and a-pinene) [709], NB-Enanthrane prepared from 9-borabicyclo[3.3.1]nonane and nopol benzyl ether) [770] and others. ... [Pg.15]


See other pages where Borane, with is mentioned: [Pg.208]    [Pg.130]    [Pg.587]    [Pg.290]    [Pg.741]    [Pg.1483]    [Pg.1645]    [Pg.1647]    [Pg.1679]    [Pg.47]    [Pg.41]    [Pg.144]    [Pg.147]    [Pg.152]    [Pg.144]    [Pg.36]    [Pg.168]    [Pg.14]    [Pg.43]    [Pg.44]    [Pg.80]    [Pg.135]    [Pg.135]   


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1,5-Cyclooctadiene, reaction with boranes

1,5-cyclooctadiene reaction with borane

2-methyl-2-butene. reaction with borane

2.3- dimethyl-2-butene, reaction with borane

Acetylene, reaction with borane

Acids reaction with boranes

Acrolein, reaction with borane

Acrolein, reaction with boranes

Aldehydes with alpine-borane

Aldehydes with deuterated alpine-borane

Aldehydes with propargylic boranes

Aldehydes, conjugated reaction with borane

Aldehydes, conjugated reaction with boranes

Aldehydes, reaction with borane enolates

Alkene reaction with borane

Alkenes alcohols with borane

Alkenes reaction with borane, isomerization

Alkenes reaction with boranes

Alkenes with borane

Alkenes with boranes

Alkynes elimination with boranes

Alkynes reaction with boranes

Allyl borane, reaction with aldehyde

Alpine borane reaction with aldehydes

Amides with borane

Amine borane, hydrogenation with

Amines with borane

Ammonia borane, reduction with

Anhydride, trifluoroacetic reaction with boranes

Asymmetric Hydroborations with Chiral Boranes

Azides reaction with boranes

B clusters in solids connections with molecular boranes

Borane , compounds with

Borane , compounds with chlorodiethoxy

Borane , compounds with derivatives

Borane , compounds with dichloroethoxy

Borane , compounds with dimeric

Borane , compounds with dimeric derivatives

Borane carbonyls reactions with

Borane catechol, reaction with

Borane complex with dimethyl sulfide

Borane complexes reaction with

Borane complexes reaction with alkynes

Borane dative bond with

Borane enantioselective allylation with

Borane hydration of alkenes enantioselective allylation with

Borane hydroboration with

Borane reacting with

Borane reaction with 3-hexyne

Borane reaction with alkynes

Borane reaction with boron trichloride

Borane reaction with halo carbonyls

Borane reactions with aldehydes

Borane reactions with benzaldehyde

Borane reagent formed with 2-aminoethanol

Borane with benzyl bromide

Borane, allyldiisopinocampheylreactions with aldehydes

Borane, allyldiisopinocampheylreactions with aldehydes asymmetric synthesis

Borane, allyldimesitylreactions with lithium amides

Borane, allyldimethoxyreactions with aldimines

Borane, allylreaction with imines

Borane, carboxy-compd. with trimethylamine

Borane, chloro-, compound with ethyl ether

Borane, compd. with thiobis[methane

Borane, crotyldiisopinocampheylboratropic shift reactions with aldehydes

Borane, crotylreactions with imines

Borane, crotylreactions with imines synthesis

Borane, derivatives addition reactions with aldehydes

Borane, dialkylcrotylisomerization reactions with carbonyl compounds

Borane, dimesitylmethylreactions with bases

Borane, diphenylhydroxyreaction with ethoxyacetylene

Borane, diphenylhydroxyreaction with ethoxyacetylene mercury acetate

Borane, electrophilicity reaction with alkenes

Borane, electrophilicity reaction with alkynes

Borane, electrophilicity reaction with carboxylic acids

Borane, triethylreaction with thioallyl anions

Borane, triethylreaction with thioallyl anions a-selectivity

Borane, with silyl-alkynes

Borane-tetrahydrofuran, reaction with

Boranes adducts with amines

Boranes alkynyl, reactions with aldehydes and ketones

Boranes amine, hydrogenation with

Boranes chloride, reaction with alkynes

Boranes cyclic, coupling with

Boranes equilibrium with diboranes

Boranes ethylene derivatives with

Boranes hydrogenations with

Boranes oxidation with NaOH

Boranes palladium-catalyzed coupling with halides

Boranes radical reactions with

Boranes reaction with

Boranes reaction with alkenes, regioselectivity

Boranes reaction with aminals

Boranes reaction with basic hydrogen peroxide

Boranes reaction with carbon

Boranes reaction with carbon dioxide

Boranes reaction with carboxylic acids

Boranes reaction with chloramine

Boranes reaction with diazo compounds

Boranes reaction with epoxides

Boranes reaction with halo carbonyl compounds

Boranes reaction with halogen

Boranes reaction with hydroperoxide anion

Boranes reactions with aldehydes

Boranes reactions with aldehydes and ketones

Boranes syntheses with

Boranes vinyl, reaction with carboxylic acids

Boranes with Two Boron-Bonded Nitrogen Atoms

Boranes with acetylides

Boranes with alkynes

Boranes with amides

Boranes with aryl halides

Boranes with diazo compounds

Boranes with halogens

Boranes with oxygen

Boranes, alkenyldialkylbrominolysis reaction with iodine

Boranes, alkenyloxyreactions with ketones

Boranes, alkenyloxyreactions with ketones synthesis

Boranes, alkenyloxyreactions with ketones via acylation of boron-stabilized carbanions

Boranes, alkoxyreaction with organometallic compounds

Boranes, alkoxyreaction with organometallic compounds formation of aldehydes

Boranes, alkyl reaction with aldehydes

Boranes, alkyldimesitylreactions with bases

Boranes, chlororeaction with acetophenone

Boranes, dialkylallylreaction with ethoxyacetylene

Boranes, elimination with alkenes

Boranes, oxidation with

Boranes, reaction with bromo esters

Boranes, reaction with chromic acid

Boranes, reaction with disulfides

Boranes, reaction with halo-derivatives

Boranes, reaction with heterocycles

Boranes, reaction with hydride

Boranes, reaction with ketenes

Boranes, reaction with oxygen

Boranes, vinylreactions with organometallic compounds

Boranes, vinylreactions with organometallic compounds synthesis

Boranes, vinylreactions with organometallic compounds via hydroboration of 1-alkynes

Boranes, with alkynes, reduction

Boranes, with alkynes, reduction acids

Boranes, with alkynes, reduction peroxide

Boranes, with metal alkyne

Boron boranes with dimethylsulfide

Bromo ketones, reaction with boranes

Carbon monoxide reaction with boranes

Carbon monoxide with boranes

Carboxylic acid reaction with borane

Carboxylic acids reduction with borane

Carboxylic acids with boranes

Cis/trans-Selective reactions with boranes

Complexes with Borane

Conjugated compounds, reaction with boranes

Conjugated dienes, reaction with borane

Copolymerization olefins, with borane monomers

Diazo compounds, alkylation with boranes

Diazo esters with boranes

Diazo ketones with boranes

Diazo reaction with boranes

Diazoketones reaction with boranes

Diborane equilibrium with borane

Dienes reaction with boranes

Diols reaction with boranes

Enantioselectivity, with Alpine borane

Enantioselectivity, with chiral boranes

Esters with boranes

Ethylenediamine borane reductions with

Exchange with boranes

Furan, tetrahydro-, compound with borane

Halo esters reaction with boranes

Halo ketones with boranes

Hydroboration with chiral boranes

Hydroperoxide anions reaction with borane

Ketone with neat Alpine-Borane

Ketones asymmetric reduction with Alpine-borane

Ketones reduction with boranes

Ketones with Alpine-Borane

Ketones with borane

Ketones, conjugated reaction with borane

Ketones, conjugated reaction with boranes

Ketones, reaction with Alpine borane

Ketones, reaction with boranes

Lactams reduction with borane

Lewis bases, complexes with borane

Malic acid reduction with borane

Methyl sulfide, compd. with borane

Nitriles, reaction with borane

Oxazaborolidine, complex with borane

Oxirane reactions with borane

Peroxides hydrogen peroxide reaction with boranes

Pyridine complex with borane

Pyridines reactions with boranes

Reaction with borane

Reduction Reaction with Borane

Reduction of ketones with borane

Reduction reactions with boranes

Reduction with borane

Reduction with boranes

Regioselectivity alkene reaction with borane

Sodium reaction with boranes

Sulfides reaction with boranes

Tetrahydrofuran complex with borane

Tetrahydrofuran complexed with borane

Thexyl borane hydroboration with

Titanium complexes with boranes

Trimethylamine, complex with borane

Unsaturated aldehydes with boranes

Unsaturated ketones with boranes

With boranes

With boranes

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