Triphenyl boron

Biphenyldiyl 2-bromo-2 -biphenyl telluronium bromide (m.p. 264°, yield 79%) and the corresponding iodine compound (m.p. 265c, yield 63%) were similarly prepared2,3. Tetraphenyl tellurium transferred an anionic phenyl group to benzaldehydc and triphenyl boron yielding triphenyl telluronium salts4. 

Tetraphenyl tellurium provided a phenyl anion in reactions with triphenyl boron, dichloromethane, chloroform, and benzaldehyde2. 

N,0 heterocyclic carbenes have also been shown to form adducts with triorganoboron complexes. Triphenyl-boron carbene adducts (62) were isolated from the reaction of an isocyanide adduct of BPhs with methanol (equation 6), in the presence of a catalytic amount of KF. An X-ray structural determination showed that (62) consists of a tetrahedrally coordinated boron atom with all four B C bond distances equal (within experimental error). 

If excess of Grignard reagent is used in the above reaction, a mixture of boron triphenyl boron diphenyl fluoride, and phenyl boron difiuoride, appears to be formed. 

The fungicidal effect of organic boron compounds is under investigation. An active substance worth mentioning is triphenyl boron which forms coordination compounds with nitrogen bases (ammonia, triethylamine, pyridine, etc.) (40). It is effective against soil fungi (Pythium spp., Rhizoctonia spp.) (Birnbaum and Anderson, 1964). 

AI3-60391 Borane, triphenyl- Borine, triphenyl EINECS 213-504-2 Triphenylborane Triphenylborine Triphenyl-boron,... 

Kouvetakis J., McElfresh M.W and Beach D.B. Chemical Vapor Deposition of Highly Conductive Boron-Doped Graphite from Triphenyl Boron // Carbon. 1994. V. 32. No 6. P. 1129-1132. 

The highest ceramic yield (80 wt%) [5] was obtained using the thermal decomposition of boronylpyridine. Other routes, such as the pyrolysis of triphenyl boron or l,2-C2BioHi2, resulted in ceramic yields of only 2 and 4 wt%, respectively [4]. 

Tetraphenyl phosphonium salts can be prepared from pentaphenylphosphorane by reaction with triphenyl boron, a hydrogen halide or an alkyl halide with ultraviolet radiation. 

With discoveries of boron-based cocatalysts such as triphenyl-boron, ammonium tetraphenylborate salts, and finally pentafiuorophenyl derivatives of borate [B(C6H5)4] , olefin polymerization catalysis was developed without a reliance on alkylaluminum species. Although the activity with nonfiuori-nated boron-based cocatalysts was invariably low, the fiuorinated analogs exhibited olefin polymerization behavior similar to that of metallocene/MAO catalyst systems. The boron and borate compoimds are typically used in a 1 1 molar ratio with transition metal (stoichiometric or near stoichiometric). Because these activators do not alkylate the transition metal, the metallocene precatalyst employed must already bear alkyl groups. Thus, zirconocene dimethyl species combine with boron or borate activators to nerate active cationic polymerization catalysts. Figure 8 shows typical activation reactions with borate (a, b) and boron (c) activators. 

Perfluorinated triphenyl boron and perfluorinated tetraphenylborate species have stoichiometric advantages compared to MAO, but they have specific drawbacks including higher cost... 

Telechelics containing quaternary ammonium salts as chain ends have been synthesized by quaternization of tertiary amines with organic halides." Unstable salts are formed by the reaction of living polymers with boranes and aluminum alkyls." However, triphenyl boron derivatives were found to be stable enough to examine spectroscopically. 

Cava and Schlessinger have reported the synthesis of 1,2,3-triphenyl-isoindole (65) in 78% yield from 1,3-diphenylisobenzofuran (68) hy reaction with thionylaniline (69) and boron trifluoride. The mechanism proposed for this remarkable transformation involves reaiTangement of the adduct (70) derived from thionylaniline and the isobenzofuran, to the tricyclic intermediate (71). This presumably collapses to the S-sultam (72), which yields the isoindole (65) upon extrusion of sulfur dioxide. Loss of sulfur dioxide, both from S-sultones and unsaturated S-sultams, is well documented. ... 

Notable examples of general synthetic procedures in Volume 47 include the synthesis of aromatic aldehydes (from dichloro-methyl methyl ether), aliphatic aldehydes (from alkyl halides and trimethylamine oxide and by oxidation of alcohols using dimethyl sulfoxide, dicyclohexylcarbodiimide, and pyridinum trifluoro-acetate the latter method is particularly useful since the conditions are so mild), carbethoxycycloalkanones (from sodium hydride, diethyl carbonate, and the cycloalkanone), m-dialkylbenzenes (from the />-isomer by isomerization with hydrogen fluoride and boron trifluoride), and the deamination of amines (by conversion to the nitrosoamide and thermolysis to the ester). Other general methods are represented by the synthesis of 1 J-difluoroolefins (from sodium chlorodifluoroacetate, triphenyl phosphine, and an aldehyde or ketone), the nitration of aromatic rings (with ni-tronium tetrafluoroborate), the reductive methylation of aromatic nitro compounds (with formaldehyde and hydrogen), the synthesis of dialkyl ketones (from carboxylic acids and iron powder), and the preparation of 1-substituted cyclopropanols (from the condensation of a 1,3-dichloro-2-propanol derivative and ethyl-... 

Two pieces of direct evidence support the manifestly plausible view that these polymerizations are propagated through the action of car-bonium ion centers. Eley and Richards have shown that triphenyl-methyl chloride is a catalyst for the polymerization of vinyl ethers in m-cresol, in which the catalyst ionizes to yield the triphenylcarbonium ion (C6H5)3C+. Secondly, A. G. Evans and Hamann showed that l,l -diphenylethylene develops an absorption band at 4340 A in the presence of boron trifluoride (and adventitious moisture) or of stannic chloride and hydrogen chloride. This band is characteristic of both the triphenylcarbonium ion and the diphenylmethylcarbonium ion. While similar observations on polymerizable monomers are precluded by intervention of polymerization before a sufficient concentration may be reached, similar ions should certainly be expected to form under the same conditions in styrene, and in certain other monomers also. In analogy with free radical polymerizations, the essential chain-propagating step may therefore be assumed to consist in the addition of monomer to a carbonium ion... 

The development of a solvent reaction between triphenyl borate and paraformaldehyde to produce a boron-modified phenolic resin that flowed at usual processing temperatures has been reported.90... 

Groups attached to aluminum or boron in this way have the expected increased electrophilic and decreased nucleophilic reactivities. For example, the complex of aluminum triphenyl and phenyl lithium lacks the usual Grignard-like reactivity of phenyl lithium towards-carbonyl compounds.800... 

Lithium phenyl is not a t5 ical ionic compoimd because of the considerable deformation of the jr-electron system of the phenyl radical anion by the lithium ion (77). However the phenyl radical anion is stabilized by boron triphenyl, which functions as EPA towards the carbanion ... 

With boron trifluoride-etherate, methanethiol and acetic acid fluorine is incorporated in almost quantitative yields. For example, the bis-dimethylamino-derivative 164 can be converted to l-fluoro-l-dimethylamino-2.4.6-triphenyl-phoshorin 172. ... 

By treating l.l-bis-dialkylamino-2.4.6-triphenyl-X -phosphorin 164 with boron trifluoride in benzene and methanethiol, Kanter obtained a 90% yield of 1-fIuoro-l-dimethylamino-2.4.6-triphenyl-X -phosphorin 772 (see p. 88). 

Treatment of 1.1-dimethoxy-2.4.6-triphenyl-X -phosphorin 183 with boron tribo-mide in methylene chloride at 0 °C results in cleavage of the methyl group from... 

A flask was charged with 4-bromo-iodobenzene (0.079 mol), 4-methoxy-2-methyl-phenyl boronic acid (0.087 mol), palladium acetate (0.004 mol), and triphenyl phosphine (0.008 mol) and then treated with 200 ml acetone and 250 ml 2M NaHCO i. The mixture was refluxed at 65°C for 18 hours and was then treated with water and diethyl ether and the organic layer isolated. This layer was washed with 40 ml saturated sodium chloride solution and water, dried over MgSC>4, filtered, and concentrated. The residue was purified by column chromatography using silica gel with CH2C12/ hexane, 1 1, and then recrystallized in / , 7 3, respectively, and 16.4 g of product isolated. 

The Onsager theory of geminate recombination was qualitatively consistent for aryl-substituted thiapyrylium salt and dialkylamino-substituted triphenyl-methane dispersed in polycarbonate film [301]. The quantum yield of Hie photogeneration was equal to 0.5 at the electric field strength of 106 V cm-1, mobility of I0 12m2 V-1 s-1. Hole and electron conductivity was established. In a triphenylamine-lexan system doped with a boron diketone acceptor, the... 

Phenyl azide-Aluminum chloride, 240 Haloboration Boron tribromide, 43 Halogenation Boron tribromide, 43 Tetrabutylammonium tribromide, 287 Hydroacylation Dicarbonyl(nitrosyl)triphenyl-phosphinecobalt, 101 Hydrofluorination... 

Diisobutylaluminum hydride-Boron trifluoride etherate, 116 Diphenylsilane-Palladium(II) chlo-ride-Triphenylphosphine, 126 Diphenylsilane-Tetrakis(triphenyl-phosphine)palladium(0)-Zinc chloride, 126... 

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