Tetrakis benzoquinone

Oxanorbomane, 2,3,5,6-tetrakis(methylene)-adduct with benzoquinone, 1, 414 7-Oxanorbomanes... 

Coordination studies of acyclic thioether ligands to silver(I) centers has also been studied. Poly(alkylthio)aromatic systems have been used to form supramolecular silver(I) compounds. With the ligand 2,3,5,6-tetrakis(isopropylthio)benzoquinone the compound has a linear chain structure in which silver(I) has a tetrahedral coordination.1156 A similar structure has the compound with the hexakis(methylthio)benzene,1157 but with the hexakis(tolylthio)benzene the silver... 

Oxanorbomane, 2,3,5,6-tetrakis(methylene)-adduct with benzoquinone, 1, 414 7-Oxanorbomanes iron carbonyl complexes structure, 4, 550 l70 NMR, 4, 580, 581 photoelectron spectroscopy, 4, 586 structure, 4, 547 Oxapenams synthesis, 7, 353... 

The kinetics of oxidation of aldehydes by the Fenton reagent [Fe(II)-H202-0H-] have been studied.89 It has been suggested that different reactivities of PhIO in iron(III)-porphyrin-catalysed alkene epoxidation may be due to the formation of a more reactive iron(IV)-0-IPh complex.90 The iron(m) complex of tetrakis(3,5-disulfonato-mesityl)porphyrin catalyses the oxidative degradation of 2,4,6-trichlorophenol to 2,6-dichloro-l,4-benzoquinone with KHSO5 as the oxygen atom donor a peroxidase-type oxidation is thought to be involved.91... 

The selective Bock Oxidation using AICI3/CH2Q2 in the meantime has formed widespread application for main group element compounds the prediction of one-electron oxidizability based on first ionization energies IEJ < 8 eV is valid also for numerous other classes of compounds. For examples of ESR/ENDOR-detected radical cations or their rearrangement products, see BN heterocycles H. Noth, W. Winterstein, W. Kaim and H. Bock, Chem. Ber., 112, 2494 (1979) tetra-teri-butyltetrahedrane H. Bock, R. Roth and G. Maier, Chem. Ber., 117, 172 (1984) tetrakis(dimethylamino)-p-benzoquinone H. Bock, P. Hanel and U. Lechner-Knoblauch, Tetrahedron Lett., 26, 5155 (1985) 1,2-dithiolane H. Bock, B. I. Chenards, P. Rittmeyer and U. Stein, Z. Naturforsch. B, 43, 177 (1988), and references cited therein. 

Takeuchi, K, Tamura, T, Jona, H, Mukaiyama, T, A novel activating agents of disarmed thioglycosides, combination of trityl tetrakis(pentafluorophenyl)borate, iodine and 2,3-dichloro-5,6-dicyano-/7-benzoquinone (DDQ), Chem. Lett., 692-693, 2000. 

The anodic oxidation of phenylenediamines parallels that of aminophenols (see Sec. III.A.l) and has been reviewed by Adams [108]. If unsubstituted at the nitrogens, the two-electron oxidation leads to the quinone dimine. This compound either undergoes hydrolysis to the quinone inline and benzoquinone, or a 1,4-addition of a nucleophile, for example, the parent phenylenediamine itself, to the quinoidal systems occurs. Further oxidation of the products may take place. In acetonitrile, the one-electron oxidation to the cation radical predominates [109]. Under these conditions,/7-phenylenediamine also leads to 1,4-coupling products [110,111]. A-Substituted phenylenediamines are forming more stable cation radicals. For example, tetrakis(/7-bromophenyl)/7-phenylenediamine ( °= 0.91V vs. NHE) and tetrakis(2,4-dibromophenyl)-/7-phenylenediamine E° = 0.94 V vs. NHE) in acetonitrile even show reversible behavior for the second oxidation step to the dication [78]. 

Muconic acid anhydride 4,6-di-t-Butyl-2H-pyra-n-2-one spiro [1,4-benzodioxin-2(3H), 2 -[2H]pyran]-3-one 4, 6,6, 8-tetrakis (1,1 -dimethylethyl) 3,5-di-t-butyl-5 (carboxymethyl) -2-furanone 3, 5-di-t-butyl-l, 2-benzoquinone... 

Oxygen and suitable catalysts can also be used for the conversion of phenol to ben-zoquinone. Thus, irradiation of phenol in the presence of [Cu(bpy)2] or [Cu(l,10-phenanthroline)] + brings about degradation by a path that shows both pH and solvent dependency . Thus in acetonitrile benzoquinone predominates, but in water carbon dioxide is the sole product. Benzoquinone can also be formed from phenol by continuous irradiation in the presence of the catalysts [Crfbpyfs] or less effectively with [Ru(bpz)3] + and [Ru(bpy)3] +. The reaction path involves 02( A ) as the oxidant . Porphyrins such as 5,10,15,20- tetrakis(2,6-dichlorophenyl)porphyrin and chlorins can also be used to convert naphthols and phenols to the corresponding quinones (Scheme 28) . Phthalocyanines immobilized on polymers have also been used as the catalyst system to effect photooxidation. ... 

A number of examples of the use of host-guest chemistry in the creation of PET active systems have appeared. The reaction of P-cyclodextrin alcoholate with meso-tetrakis(pentafluorophenyl)porphyrin is reported to give a hydrophilic cyclodextrin-porphyrin conjugate in 14% yield. ° In the presence of guests such as 1,4-benzoquinone, anthraquinone-2-sufonate or 8-anilino-l-naphthalene sulfonic acid, PET operates as evidenced by the fluorescence... 

Of the three tetrakis(alkanoyloxy)benzoquinone homologs (n-TBQ) that have been reported, the hexanoyloxy homolog (6-TBQ) is not liquid crystalline, but the heptanoyloxy and octanoyloxy (7- and 8-TBQ) form enantiotropic D phases over small (2-3 ) temperature ranges [106]. These molecules have shapes that are intermediate between the rods of 1, 4-disubstituted cores and the disks of hexasubstituted ones, and yet they are able to stack in mesomorphic columns. 

Two new ligands N,N-bis(3,5-dimethylpyrazol-l-ylmethyl)benzylamine, bpmba, and N,N,N, N tetrakis(3,5-dimethylpyrazol-l-ylmethyl)-a,a -diamino-/n-xylene. bpmdx have recently been synthesized [26] their copper complexes are active catalysts for the oxidation of catechol to 0 benzoquinone. 

Currently, we note that the highest degree of interpenetration is the elevenfold hydrogen bonded diamond net of the 1 2 adduct of tetrakis(4-(3-hydroxyphenyl)phenyl)methane and benzoquinone, [9] and the ten fold diamond net in [Ag(l,12-dodecanedinitrile)2]N03 [10]. 

Ring-closing metathesis Ring-lluorinated diazines Statistical substituent chemical shift Tetra-n-butylammonium fluoride Tert-butyldimethylsilyl Tetrachloro-1,4-benzoquinone Tetrakis(dimethylamino)ethylene Triethylamine... 

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