Phosphorous reaction with quinone

Reaction of quinone diimines with phosphorous acid esters... 

It is of interest to note that attachment of a basic side chain on carbon of an isomeric dibenzazepine affords a compound in which anticholinergic activity predominates, elantrine (50). Reaction of anthra-quinone (45) with the Grignard reagent from 3-chloro-N,N-dimethylaminopropane in THF in the cold results in addition to but one of the carbonyl groups to yield hydroxyketone 46. This is then converted to oxime 47 in a straightforward manner. Treatment of that intermediate with a mixture of phosphoric and polyphosphoric acids results in net dehydration of... 

A variation of the ketone to alkene transformation is conversion of quinones into arenes, for which a number of reagent systems have been employed. Over a century ago, the reduction of polycyclic quinones to aromatic systems with phosphorous and hydroiodic acid at elevated temperatures was reported. These conditions, however, resulted in complex reaction mixtures consisting of phenols and polyhydrogenated products. More recently, Konieczny and Harvey have reported the reduction of qui-... 

The process suffers from several drawbacks. For instance, the solvent must be able to dissolve both the apolar anthraquinone and the more polar hydroquinone and, at the same time, to provide immiscibility with water in order to allow the recovery of hydrogen peroxide. Complex mixtures of solvents are used, usually formed by an aromatic compound to dissolve the anthraquinone (toluene, methylnaphthalene) and a polar solvent to dissolve the hydroquinone (organic esters of phosphoric acid, diisobutylcarbinol, etc.). Even so, some derivatives of the quinone formed under the reaction conditions, particularly tetra- and octa-hydro derivatives are poorly soluble in the working solution. 

Electrochemical corrosion of carbon supports was widely studied in the context of phosphoric acid fuel cell development (Antonucci et al. 1988 Kinoshita 1988), but recently also the low-temperature fuel cell community paid more attention to this process (Kangasniemi et al. 2004 Roen et al. 2004). Carbon corrosion in fuel cell cathodes in the form of surface oxidation leads to functionalization of the carbon surface (e.g., quinones, lactones, carboxylic acids, etc.), with a concomitant change in the surface properties, which clearly results in changes of the hydrophobicity of the catalyst layer. Additionally, and even more severe, total oxidation of the carbon with the overall reaction... 

Stiixe and coworkers (90—93) have condensed appropriately substituted quinones with amino-phenols to yield isolable, single-stranded intermediates which may be converted to ladder structures by treatment at higher temperature. Alternatively, the reaction may be carried out at high temperature in a polar, aprotic solvent such as hexamethyl phosphor-amide (HMP) to 3deld the ladder poljmer directly. 

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