4-phenyl- tetraphenylborate

Oxatellurinanium 4-Phenyl-(Tetraphenylborate) E12b. 691 (R2TeI2 + Ar4B )... 

Organoboranes are reactive compounds for cross-coupling[277]. The synthesis of humulene (83) by the intramolecular cross-coupling of allylic bromide with alkenylborane is an example[278]. The reaction of vinyiborane with vinyl-oxirane (425) affords the homoallylic alcohol 426 by 1,2-addition as main products and the allylic alcohol 427 by 1,4-addition as a minor product[279]. Two phenyl groups in sodium tetraphenylborate (428) are used for the coupling with allylic acetate[280] or allyl chloride[33,28l]. 

Experience in PTC with cationic catalysts showed that, in general, the most suitable compounds have symmetrical structures, are lipophilic, and have the active cationic charge centrally located or sterically shielded by substituents. For anionic catalysis sodium tetraphenylborate fulfills these conditions, but it is not stable under acidic conditions. However, certain derivatives of this compound, namely sodium tetra-kis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB, 12.162) and sodium tetrakis[3,5-bis-(l,l,l,3,3,3-hexafluoro-2-methoxy-2-propyl)phenyl]borate (HFPB) are sufficiently stable to be used as PTC catalysts for azo coupling reactions (Iwamoto et al., 1983b 1984 Nishida et al., 1984). These fluorinated tetraphenylborates were found to catalyze strongly azo coupling reactions, some of which were carried out with the corresponding diazotization in situ. 

Sladek, A., Hofreiter, S., Paul, M. and Schmidbaur, H. (1995) Sodium tetraphenylborate as a phenylating agent for gold(I) complexes. Journal... 

Suitable electrolytes for the aqueous phase (w) comprise, for example, LiCl, HCl, MgCl2, MgS04, while suitable electrolytes for the organic phase (o) comprise salts of, for example, tetrabutylammonium, tetraphenylarsonium, or bis(triphenyl-phosphoranylidene)ammonium cations with tetraphenylborate, tertrakis(4-chloro-phenyl)borate, or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate anion. 

FIG. 10 Faradaic admittance coefficient Yq for the interface between 0.1 M LiCl in water and 0.02 M tetrabutylammonium tetraphenylborate ( ) or tetrapentylammonium tetrakis[3,5-bis(tri-fluoromethyl)phenyl]borate ( ) in o-nitrophenyl octyl ether as a function of the interfacial potential difference A y. (From Ref 73.)... 

Due to its stability and water-solubility sodium tetraphenylborate is a particularly convenient starting material for such reactions. Several halogenated heterocycles were phenylated with NaBPlu in aqueous solution with [Pd(OAc)2] catalyst under microwave irradiation (Scheme 6.13) [36]. All reactions were mn under argon in Teflon-closed pressure tubes. It is not easy to compare these results to those of thermal reactions, since the temperature of the irradiated samples is not known precisely. Nevertheless, the microwave method is certainly very effective since 8-12 min irradiation at 100-160 W power allowed the isolation of 60-85 % phenylated products. 

BAs we have shown above, interpretation of weak interactions is difficult even in the case of the complex CH4 HX, where HX is a pronounced proton donor. It is obvious that interactions C-H- H-C are more questionable in this sense. Nevertheless, a number of intermolecular C-H- H-C contacts, which are smaller than 3 A, have been observed for example, in the crystal structures of the organoammonium tetraphenylborate system [40], Primarily, these H H contacts are observed between hydrogen atoms in the phenyl rings located in neighboring... 

The microwave-promoted palladium-catalysed phenylation of aroyl chlorides utilising sodium tetraphenylborate to yield unsymmetrical ketones was reported by Wang. The use of potassium fluoride as a base was found to give higher yields than potassium carbonate or triethylamine under the reaction conditions tested30 (Scheme 2.4). 

Interestingly, [AuPhCP Bus)] can also be obtained in quantitative yield in a slow reaction of tris [tri(ferf-butyl)phosphine]gold(I) oxonium tetrafluoroborate with sodium tetraphenylborate as phenylating agent22 [Eq. (2)]. 

Sodium tetraphenylborate converted heterocyclic tellurium diiodides in refluxing ethanol to 7h-phenyl-telluroniacycloalkane tetraphenyl borates5 8. 

Dimethyl Phenyl Telluronium Tetraphenylborate1 0.46 g (2 mmol) of dimethyl telluronium dichloride are dissolved in 30 ml of absolute methanol and a solution of 1.7 g (5 mmol) of sodium tetraphenylborate in 30 ml of methanol is added dropwise with stirring at 20°. Stirring is continued for 2 h, the mixture is filtered, and the solid is recrystallized from ethyl methyl ketone yield 0,81 g (65%) decomposes above 200°. 

Methyl-l-phenyl-tellurolanium Tetraphenylborate A mixture of 4.52 g (10 mmol) 2-methyl-telIuroIane-... 

Complex 125 in which one phenyl group of BPh4 is it bonded to ruthenium, has been synthesized in low yield (20%) by reaction of compound 129 with sodium tetraphenylborate in boiling methanol (80,81) [Eq. (12)]. The zwitterionic structure has been confirmed by X-ray structural analysis (82). 

Dimethyl and methyl phenyl 4,4-dimethyl-2,6-dioxocyclohexylidene tellurium compounds transferred a methyl group to triethylamine, triphenylphosphane, tris[di-methylamino]phosphane, and triphenylarsane. The methyl onium cations were isolated as tetraphenylborates. The alkylidene organo telluronium intermediate was identified by P-NMR spectroscopy in the reaction of the ylide with tris[dimethylamino]phosphanek... 

Reaction of sodium dithiocarbamate with an equimolar amount of the chloroacetaldehyde/sodium hydrogen sulfite adduct (110) in dimethyl-formamide at room temperature yields 111 quantitatively. The latter, treated first with concentrated sulfuric acid and then with sodium tetraphenylborate, gives the salt 112 in 86% yield.Under the same conditions, piperi-dinium dithiobenzoate reacts with 110 providing in 64% yield 2-phenyl-l,3-dithiolium tetraphenylborate. ... 

Various aromatic amines, phenols, and compounds containing active methylene groups can be titrated with arenediazonium salts, from which 4-bromo-l-naphthale-nediazonium chloride seems to be the most widely applicable titrant. Compounds that react slowly with arenediazonium salts can be determined by back-titration when the excess of arenediazonium salt is back-titrated with either sodium tetraphenylborate or 2,4-diaminotoluene. Indirect determination is useful for secondary amines, which react with arenediazonium ions to form triazenes. The determination of diazonium salts of ampholytic character is based on the reaction of these salts with l-phenyl-3-methyl-5-pyrazolone, the excess of which is titrated with 4-bromo-l-naphthalenediazonium chloride solution. 

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