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O-Benzoquinone diimine

Lastly, mention should be made of an original scheme of access195 to an iminophos-phane (124) aminophosphorane (124a) equilibrium starting from PPh3 and an o-benzoquinone diimine derivative (125) (Scheme 30). [Pg.227]

The cycloaddition reaction (333)+ (334) — (335) illustrates the preparation of tetrahydro-quinoxalines from o-benzoquinone diimines. [Pg.639]

By a novel photochemical process the intense colored cobalt /V-phenyl-O-benzoquinone diimine complex (78) is formed which involves the irradiation of thermally stable Co(ij5-Cp)(Ph2N4) (equation 17). This unusual transformation most probably occurs via an intramolecular path-... [Pg.222]

Reaction of RuC13 with o-phenylenediamine in the presence of Zn yields the tris(diimine) complex of o-benzoquinone diimine.599... [Pg.322]

Finally in this section, the coordinated o-benzoquinone diimine structure (77ab) has been shown to undergo a facile cheletropic reaction with triphenylphosphine to give 2,3-dihydro l,3,2X -benzodiazaphospholes (78ab) which equilibrate to the iminophosphoranes (79ab) in moderate yields. ... [Pg.59]

Azodicarbonyl compounds in synthesis of heteroeycies 82AHC(30)l. Azodicarboxylate and Ph3P in synthesis of heteroeycies 8 IS I. o-Benzoquinone diimines in heterocyclic synthesis 81 H( 16) 1009. [Pg.283]

Benzodithiole-3-thione, 226 Benzofuroxan, 283 p-Benzoquinone, 105 O-Benzoquinone diimine, 275 Benzoylazirine, 58 Benzoylsulfene, 220, 232, 244 Benzylidenemalonaldehyde, 181 Benzyne, 243, 277, 306 Berberine, 282... [Pg.186]

Early studies on the dimerization of substituted o-benzoquinone diimines and their reactions with diarylketenes [Eq. (57)] ... [Pg.275]

Ru(acac)2(R-o-benzoquinone-diimine) complexes IR, Raman, UV-Vis B3LYP/LanL2DZ PCM 105... [Pg.241]

W. Freidrichesen and A. Bottcher, Recent Developments in the Chemistry of o-Benzoquinone-diimines ,//(Cterocycfes, 1981, 16, 1009. [Pg.391]

Fonseca T, Gigante B, Marques MM, Gilchrist TL, De CE (2004) Synthesis and antiviral evaluation of benzimidazoles, quinoxalines and indoles from dehydroabietic acid. Bioorg Med Chem 12(1) 103-112. doi 10.1016/j.bmc.2003.10.013 Friedrichsen W, Bottcher A (1981) Recent developments in the chemistry of o-benzoquinone-diimines heterocycles 16(6) 1009-1034. doi 10.3987/R-1981-06-1009 Friedrichsen W, Schmidt R (1978) Cycloadditionen mit o-benzochinon-diiminen, n. Reaktionen von o-benzochinon-diiminen mit olefinen. Liebigs Ann Chem 1978(7) 1129-1138. doi 10. 1002/jlac.l97819780712... [Pg.111]

Chapter 2 covers recent advances in the Synthesis of Quinoxalines involving the methods based on the (a) condensation of 1,2-diaminobenzenes and derivatives with various two-carbon unit suppliers, (b) condensation of o-benzoquinone diimines and diimides with various two-carbon unit suppliers, (c) condensation of A,A-dimethyl(dibenzyl)ethylenediamine with 1,2- and 1,4-dihydroxybenzenes, (d) synthesis of quinoxalines from aniline and its derivatives, (e) synthesis of quinoxalines from heterocyclic systems and (f) synthesis of quinoxalines based on the carbocyclic system. [Pg.442]

Let us now illustrate some significant examples of the redox propensity of related (but less widely studied61) quinone diimines. As happens for 1,2-dioxolenes, such ligands also exhibit the reversible electron transfer sequence o-benzoquinone diiminejo-benzosemiquinone diimine monoanion/ o-phenylendiamine dianion illustrated in Scheme 4. [Pg.353]

The generation and reactions of arylnitrenes continue to attract attention. Evidence for a photoinitiated autocatalytic chain mechanism in the photodecomposition of phenyl azide has been reported, and the reaction of photochemically generated phenyl nitrene with oxygen has been reexamined. Irradiation of p-azidoaniline in aqueous solution yields triplet p-aminophenyl nitrene, which on reaction with water is converted into the highly reactive p-benzoquinone diimine. Both m- and p-nitrophenyl azides, on photoelimination of nitrogen at 77 K, afford the corresponding nitrenes, whereas o-nitrophenyl azide (93) is converted without the intermediacy of a nitrene into the benzofurazan (94). 4,4 -... [Pg.452]

Cycloadditions of monoalkoxy- or monoaminosilylenes were observed also by cothermolyses of Mc2Si2X4 (X = OMe, NMe2) with various conjugated 1-mono- and 1,4-diheterodienes. Iminoketones, diimines and 0t,a -dipyridyl, also benzil or 3,5-di-/ert-butyl-o-benzoquinone in low yields, gave [l+4]-cycloaddition products. Unsaturated ketones or imines furnished double-bond isomers, oxa- or azasilacyclopent-3-enes and -4-enes (Scheme 2). The 4-enes are usually the main... [Pg.71]

Willstatter and collaborators discovered o-benzoquinone (I) by oxidising a solution of catechol in ether by silver oxide, and prepared />-quinoneimine (II) and diimine (III) by the similar oxidation of />-aminophenol and p-phenylenediamine ... [Pg.861]

As in the case of o-dioxolenes, the diimine derivatives also form tris-complexes. Figure 38 for instance shows the molecular structure of the benzoquinone diimino dication [Osn(bqdi)3]2 +. 50c... [Pg.354]

See other pages where O-Benzoquinone diimine is mentioned: [Pg.506]    [Pg.321]    [Pg.275]    [Pg.196]    [Pg.49]    [Pg.51]    [Pg.307]    [Pg.506]    [Pg.321]    [Pg.275]    [Pg.196]    [Pg.49]    [Pg.51]    [Pg.307]    [Pg.382]    [Pg.123]    [Pg.553]    [Pg.123]    [Pg.52]    [Pg.3964]    [Pg.254]   
See also in sourсe #XX -- [ Pg.275 ]



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