Benzene, 1,2,4-triaryl

Syntheses and Properties of 2,4,6-Triarylated Benzene Derivatives with NH2, NHR, NR2, CH2R and SH Substituents in Position 1... 

The cis-oriented poly(arylacetylenes) so formed, were found to depoly-merize selectively at 200-225°C to the corresponding 1,3,5-triaryl-benzenes derivatives. 

Several examples of poly- and oligomerization of acetylenes are also quite typical. Water-soluble rhodium complexes with hydrophilic phosphine ligands catalyze the polymerization of arylacetylenes into stereoregular cis-oriented poly(arylacetylenes), which can further be selectively depolymerized on heating to provide a convenient method for the preparation of triaryl-benzenes [194]. Different types of product formed by regioselective di- and trimerization can be obtained by the reaction of such catalysts with other kinds of terminal acetylenes [195]. 

Ueno studied a series of different triaryl- or tetraaryl-benzene host materials and found that using triarylbenzene (TPB3, 190) (Scheme 3.58) as a host material with a DSA-amine (Ide 102, 191) doped OLED showed a peak luminance of 142,000 cd/m2 at 12 V. This device also showed a luminescent efficiency of 6.0 lm/W at 5 V and 820 cd/m2 and an external efficiency of 2.4%. The lifetime of the device is also better than that of a device with DPVBI as the host. 

Carbonation and subsequent hydrolysis of either lithiated or sodiated metallocenes lead to the corresponding carboxylic acids. Ferrocenecarboxylic acid and ferrocene-1,1 -dicarboxylic acid are readily produced in this manner and can be conveniently separated by extraction of the former with ethyl ether or benzene. The reaction of metalated ferrocenes with various chlorosilanes has led to a variety of triaryl- or trialkvlsilylferrocenes (3, 28, 90). 

Trialkyl- or triaryl-l,l-dihalo-A5-phosphorine 12(1 mmol) was stirred in benzene (10 mL) with AgBF (2.2equiv) for 1 h at rt. The solution was shaken with H20, the organic phase was dried (Na2SO ), the solvent was evaporated and the residue was recrystallized (MeOH). 

Pyrylium salts, especially the 2,4,6-triaryl substituted, react with a wide variety of nucleophiles some of which lead to the formation of rings other than benzene or pyridine. Sodium sulphide, for instance, attacks the pyrylium ring at C-2 to produce the blue-coloured dienone (78) which then cyclizes on treatment with add to the thiopyrylium salt (79) (56HCA207). 

Tellurium tetrachloride and phenols condense at elevated temperatures to form triaryl telluronium chlorides1,2. The reaction with benzene in refluxing benzene required the presence of aluminum trichloride3. 

The most sensitive spectrophotometric methods for the determination of Re involve the extraction of ion-associates formed by Re04" with basic dyes. From among the triaryl methane dyes, use has been made of Methyl Green (benzene, e = 1.2-10 at 640 nm) [37], fuchsine (formula 27.1) [1] Brilliant Green (benzene, e = 1.010 ) [38], Crystal Violet [39], Victoria Blue 4R (formula 4.28) [40], Rhodamine B [41], Safranine T [42], Nile Blue... 

Three types of pentavalent arylbismuth derivatives can be used for the arylation of phenols. They derive from the triaryl, the tetraaryl and the pentaaryl series. The C-arylation of phenolic compounds can be performed by triarylbismuth carbonate, the presence of a base being not mandatory. It can also be realized by a variety of pentavalent triarylbismuth compounds and tetraarylbismuthonium salts, both in the presence of a base, in various solvents (methylene chloride, benzene, toluene or... 

Returning to the triaryl-X template, we can see that tethering the closed circles in a cycle provides the basis for a trioxatricornan structure (147). Capping the trioxatricornan structure with a benzene ring creates a cyclophane... 

Oxidation of triaryl alanes is less well defined than that of the aliphatic compounds. Tri-p-tolylalanc, for example, gives only an 8% yield of p-cresol (81). The reaction in ether as solvent is even more involved as the diluent clearly participates in the reaction (215). Following oxidation of triphenyl-alane and hydrolysis, it was possible to isolate phenol, acetophenone, acetaldehyde, and benzene. The latter clearly arose from unreacted phenyl groups of the triphenylalane (215). Participation of the solvent in the reaction was also established in a study of the autoxidation of triphenylalane in C14-labeled benzene, in which C14-labeled phenol and biphenyl were isolated after hydrolysis (216). 

The mass spectra of phosphorus-containing heterocycles has frequently been applied for characterization and identification. Parent ions are frequently intense. Fragmentation patterns occasionally give a clue to the reactions taking place in the gas phase. 2,4,6-Triaryl-l,3-azaphosphinines show fragment ions as indicated in Figure 4, which are simply explained on the basis of cycloreversion reactions of the intermediate 3-aza-l-phosphabicyclo[2.2.0]hexadienes (azaphospha-Dewar benzenes). 

The photochemistry of aluminum aryls bears certain features in common with boron aryls the low reactivity of the monomeric triaryl-metallic, the formation of biaryls in tetracoordinate systems having proximate aryl groups and the formation of subvalent metallic products (22-24). Thus, when irradiated at 254 nm in ethyl ether solution, triphenylaluminum ethyl etherate underwent no formation of biphenyl or aluminum metal. On the other hand, the irradiation of triphenylaluminum (99) in benzene or toluene solution, in which the aluminum aryl is largely dimeric, led to the production of biphenyl (45%) and aluminum metal. When such a reaction mixture was filtered to remove the aluminum and the filtrate treated with D2O, hydrogen gas was evolved that consisted of >98% H—D. The biphenyl now isolated was 20% undeuterated and 80% monodeuterated further spectral comparisons showed that the deuteron was at the 2-position. These findings indicated the formation of an aluminum-hydride and an o-biphenylyl aluminum bond [Eq. (47)]. The source of the hydrogen in H—D was not the... 

Interestingly, N-phenyl-2-thiophenecarboxamides undergo 2,3,5-triarylation accompanied by a formal decarbamoylation upon treatment with excess bromo-benzenes (Equation 10.50) [74]. The reaction involves an initial coordination-assisted 3-arylation and successive decarbamoylation which is promoted by a Pd(II) species and the stoichiometric base. A related decarboxylative arylation of 2-thiophenecarboxylic acids at the ipso-position has been reported (Equation 10.51) [75]. The introduction of an electron-withdrawing group at the 3-position of thiophene makes the 4-arylation possible, while the reaction at 2- and 5-positions precedes. Thus, the reaction of 3-cyanothiophene affords the corresponding 2,4,5-triarylated products (Equation 10.52) [74]. Whilst the mechanism for the 4-... 

A brief summary has appeared on the use of carbohydrate precursors for the synthesis of chiral acyclic, heterocyclic, and carbocyclic compounds. The reaction of monosaccharides (e.g. o-mannose) with benzene or toluene in liquid hydrogen fluoride yielded l,l,2-triaryl-l,2-dideoxyalditols [e.g. (658)] that were further transformed into condensed aromatic hydrocarbons [e.g. (659) and purpuricene (660)]." ... 

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