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Phenyl borane

The formation of ethers such as 1806 by EtsSiH 84b can also be catalyzed by trityl perchlorate to convert, e.g., benzaldehyde in 84% yield into dibenzyl ether 1817 [48]. The combination of methyl phenethyl ketone 1813 with O-silylated 3-phenyl-n-pro-panol 1818, in the presence of trityl perchlorate, leads to the mixed ether 1819 in 68% yield [48] (Scheme 12.15). Instead of trityl perchlorate, the combination of trityl chloride with MesSiH 84a or EtsSiH 84b and sodium tetrakis[3,5-bis-(trifluoro-methyl)phenyl]borane as catalyst reduces carbonyl groups to ethers or olefins [49]. Employing TMSOTf 20 as catalyst gives very high yields of ethers. Thus benzaldehyde reacts with O-silylated allyl alcohol or O-silylated cyclohexanol to give the... [Pg.269]

To PhBCl2 (2 g, 13 mmol) in a 50-mL round-bottomed flask equipped with a short Vigreux column and a distillation head was added NaBF4 (3 g, 28 mmol) and the mixture was heated until the product distilled. The distillate [difluoro(phenyl)borane] distilled at 78 JC under atmospheric pressure. [Pg.614]

Fluorodehalination of the halo(phenyl)boranes with other alkali metal salts was carried out using the same procedure. [Pg.614]

Lewis superacids, such as SbF5, AsF5, PF5, TaF5, NbF5, BF3, tris(pentafluoro-phenyl) borane, boron tris(trifluoromethanesulfonate), and aprotic organic superacids developed by Vol pin and co-workers. [Pg.10]

Dichloro(phenyl)borane is a clear liquid. It is sensitive to water, hydrolyzing to di hydroxy (phenyl) borane C6H5B(OH)2. [Pg.36]

It is most conveniently stored in glass ampuls. Several other preparations for this compound are known including reactions of dihydroxy(phenyl)borane and boron trichloride12 13 or phosphorus pentachloride,14 2,4,6-triphenylboroxin, [C6H5BO]3, with phosphorus pentachloride,14 phenyl mercury chloride with boron trichloride,15 and benzene with boron trichloride.16... [Pg.37]

The construction of a borole ring that is part of a metal complex from zirconium-coordinated 1,3-dienes and tris(pentafluorophenyl)borane has been recently introduced. Tris(pentafluoro-phenyl)borane is widely used as an activator of metallocene-based polymerization catalysts because of its resistance to aryl-transfer reactions, it acts as the boron source. The reaction utilizes the zwitterionic 14-electron bis(allyl)zirconium complexes 72 and 73 which are converted to the corresponding complexes 74 and 75 via activation of one of the C-H bonds of the B-CH2 moiety... [Pg.1235]

Chiral Reagent The diamino phenyl borane (6) derived from (15,25)-l,2-diaminocyclohexane has been used as a chiral proton source for the enantioselective protonation of prochiral cyclic lithium enolates, with ee s up to 93% (eq 9). (15,25)-1,2-Dia-minocyclohexane proved to be highly superior to 1,2-diphenyl ethylenediamine or bis-naphthylamine. [Pg.203]

The reaction of neutral bis- and tris(pentafluoro-phenyl)boranes with silica surfaces can also lead to supported ionic activators. B(C6Fs)3 acts as a Lewis acid toward the surface hydroxyl groups of silica. [Pg.481]

Tri phenyl arsi rroa de Tri phenyl bi smut hi ne Tri phenyl borane... [Pg.680]

Mechanistic studies of the activation of H2 on combination of bis(2,4,6-tris(trifluoromethyl) phenyl)borane (T) with NEt3 or DABCO suggest that H2 is activated in a stepwise manner with T/NEt3, but in a concerted way with the T/DABCO system. This change in the reaction mechanism had been attributed to the different steric demand of the Lewis bases." ... [Pg.187]

Later, Tamm and coworkers investigated the combination of l,3-bis(di-tert-butylphenyl)imidazolin-2-ylidene with a new the fluorinated borane, tris[3,5-bis (trifluoromethyl)phenyl]borane (B(w-XyFg)3), which offers thermally induced FLP reactivity with, for example, CO2, C—H bonds, and H2. Again, however, this FLP tends to form abnormal NHC-borane adducts [100]. The number of FLP combinations involving carbenes is constantly growing and there are a number that have not been included here. Tamm and coworkers have recently published a detailed review specifically of NHCs in FLP chemistry [101]. [Pg.470]

Metallocene-catalysts were successfully applied as initiators for the GTP [302, 318,319], Especially adducts of group 4 metallocene-enolates and tris(pentafluoro-phenyl)boranes lead to a rapid polymerization by means of group transfer polymerization of MVK [320] ... [Pg.636]

Following these observations, the influence of various borane-derived Lewis acids was probed by Yoshimura and co-workers [28]. Triethylborane exhibited no beneficial effect and difluoro(phenyl)borane was found to have a weaker catalytic activity than acetic acid. However, boron trifluoride and ethoxy diflu-oroborane showed stronger catalytic effects than acetic acid in the initial stage... [Pg.121]

Fourteen new tricarbonylchromium complexes of benzodiazaboroles, phenyl-boranes and related compounds have been prepared and characterired. In all compounds n.m.r. data indicate that the Cr(CO)8 moiety is bonded to the benzo and phenyl rings. New types of co-ordination compounds of chromium, molybdenum, and tungsten with phosphino-aminoboranes of general formula (COsMPRSBRS, (CO)4M(PRia)aBR , and (CO)3M(PRS)B have been synthesized. Suitably substituted carbonyl compounds of the same metals reportedly react with l-phenyl-4,5-dihydroborepin (35) to yield stable complexes in which the boron atom apparently participates in metal-ligand bonding. "... [Pg.47]

Pentaphenylborole, a formally anti-aromatic compound that can be prepared by reaction of 1,1-dibutyl-2,3,4,5-tetraphenylstannole with dichloro(phenyl)-borane, is reduced by potassium to the formally aromatic dianion, and acts as a four-electron ligand in forming transition-metal complexes. ... [Pg.42]

Phenylboronic acid, lOCI, 9CI. Phenylboric acid. Benzeneboronic acid. Dihydroxy phenyl)borane [98-80-6]... [Pg.781]


See other pages where Phenyl borane is mentioned: [Pg.322]    [Pg.614]    [Pg.452]    [Pg.35]    [Pg.35]    [Pg.36]    [Pg.36]    [Pg.36]    [Pg.89]    [Pg.623]    [Pg.601]    [Pg.259]    [Pg.73]    [Pg.44]    [Pg.44]    [Pg.462]    [Pg.462]    [Pg.61]    [Pg.313]    [Pg.303]    [Pg.1007]   
See also in sourсe #XX -- [ Pg.381 ]




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