Para-dinitrobenzene

Yang and Burton studied reductive radical additions of iododifluoroacetate 37 to olefins 38 and dienes catalyzed by 6-17 mol% of a catalyst generated from NiCl2 and stoichiometric amounts of zinc in the presence of water (Fig. 8) [90, 91]. Olefins gave the reductive addition products 40a in 60-83% yield, while 1,5-hexadiene or 1,8-nonadiene provided double addition products exclusively in 55% and 73% yield. 1,7-Hexadiene gave an inseparable mixture of the expected acyclic double addition product and a tandem addition/cyclization product, in which the former dominated. The radical nature of the addition is supported by inhibition of the reaction by para-dinitrobenzene. The reaction proceeds probably via initially formed atom transfer product 39, which is subsequently reduced by nickel(0) and zinc. This is supported by deuterium incorporation, when D20 was used instead of water. No deuterium incorporation was observed with THF-dg, thus ruling out hydrogen transfer from the solvent. 

FIGURE n. Quenching of Ru(bipy) by nitrobenzene derivatives in acetonitrile solutions. Dependence of the observed emission quenching rate constant, kg, on the reduction potential of the quencher (245). T) para-Ni tronitrosobenzene, 2) para-Dinitrobenzene,... 

Ortho and para dinitrobenzene can be produced using alternative methods. 

The SET reactions can be initiated by organic anions such as carbanions and heteroatom anions, reducing organic reagents such as tetrakis(N,N-dimethylamino)ethene, low valent metal, and electrochemical reduction. Irradiation by UV light is sometimes useful for the acceleration of SET reactions, but it is not necessarily required when good electron donors, for instance thiolates instead of thiols, are used. The chain reactions of, in particular, less reactive perfluoroalkyl bromides are inhibited by species such as nitrobenzene, para-dinitrobenzene, and hydroquinone [3,6]. The reactivity order of perfluoroalkyl hahdes... 

Synonyms/Trade Names para-Dinitrobenzene 1,4-Dinitrobenzene... 

There are three possible isomers of benzene with two nitro groups attached. These Ihree isomers are named ortho-, meta-, and para-dinitrobenzene ... 

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