3276-35-5Relevant academic research and scientific papers
Cleavage reactions of radical anions that range from homolytic to heterolytic within the same family of compounds
Zheng, Zi-Rong,Evans, Dennis H.,Chan-Shing, Elisa Soazara,Lessard, Jean
, p. 9429 - 9434 (2007/10/03)
Properties of the radical anions of three α-nitrocumenes, (α-nitrocumene, p-cyano-α-nitrocumene, and p-nitro-α-nitrocumene, 1a-c) have been determined by electrochemical methods. In particular, the standard potentials of the neutral/radical anion couples were found to be -2.20, -2.04, and -1.43 V with respect to the ferrocenium ion/ferrocene potential and the rate constants for expulsion of nitrite from the radical anions were 3 × 106, 5 × 106, and 240 s-1 for 1a-c, respectively. Comparison of these potentials with those of related compounds demonstrates that reduction of the nitroalkyl portion of the molecule occurs in 1a and 1b while in 1c the electron is added to the nitrophenyl group. Thus, using previously defined terminology, the cleavage of the radical anions of 1a and 1b to give nitrite and the corresponding cumyl radicals are examples of homolytic cleavage reactions but the cleavage of the radical anion of 1c is heterolytic. The driving force for the three cleavage reactions has been estimated and it is concluded that the large decrease in magnitude of the cleavage rate constants on going from 1a and 1b to 1c is mainly due to the much larger driving force for the first two.
The kinetics and mechanism of the reaction of p-nitrocumyl bromide with nitrite ions in dimethyl sulfoxide. Evidence for a non-chain reaction giving a high nitro/nitrite ratio in the product
Paine, Stuart W.,Ridd, John H.
, p. 2577 - 2581 (2007/10/03)
The reaction of p-nitrocumyl bromide (RBr) with sodium nitrite in [2H6]dimethyl sulfoxide gives none of the conventional evidence for an SRN1 chain reaction but the initial values of the [RNO2]/[RONO] ratio (2.5
CONCERNING THE MECHANISM OF DISPLACEMENT OF NITRO GROUPS FROM ACTIVATED AROMATIC SYSTEMS
Denney, Donald B.,Denney, Dorothy Z.,Perez, Airan Jun
, p. 4463 - 4476 (2007/10/02)
The photostimulated reactions of p-nitrobenzophenone and p-nitrobenzonitrile with a variety of nucleophiles have been investigated.Displacement of the nitro group is observed in all cases.The rates of the reactions were measured by FT-IR.The rates were slowed by substances such as sulfur, air, Galvinoxyl and p-benzoquinone.In several cases rates of loss of starting material were monitored by quenching the reaction mixtures and isolating product and starting material.These reactions also showed inhibition of their rates in the presence of inhibitors.These results indicate that the reactions are chain processes.It is concluded that the substrates are converted into their corresponding radical anions which then react with the nucleophiles in a bimolecular displacement reaction.The alternate mechanism, which involves dissociation of the radical anions, is precluded because they are known not to dissociate. Key words: Stable radical anions, nucleophilic displacements
Electron-Transfer Substitution Reactions: Leaving Groups
Kornblum, Nathan,Ackermann, Peter,Manthey, Joseph W.,Musser, Michael T.,Pinnick, Harold W.,et al.
, p. 1475 - 1481 (2007/10/02)
A number of groups that do not participate in SN2 displacement processes are able to function as leaving groups in electron-transfer chain reactions at room temperature; such groups include azide, sulfone, ethers, nitro, quaternary ammonium ions, esters, and thioethers.Even carbanions are able to function as leaving groups as can be seen from fragmentation of carbon-carbon bonds.
Electron-transfer substitution reactions: The p-nitrocumyl system
Kornblum, Nathan,Cheng, Leung,Davies, Thomas M.,Earl, Gary W.,Holy, Norman L.,Kerber, Robert C.,Kestner, Melvin M.,Manthey, Joseph W.,Musser, Michael T.,Pinnick, Harold W.,Snow, Donald H.,Stuchal, Francis W.,Swiger, Roger T.
, p. 196 - 204 (2007/10/02)
Facile substitution reactions at the tertiary carbon of p-nitrocumyl chloride and α,p-dinitrocumene are described. These reactions occur with a wide range of organic and inorganic nucleophiles and are noteworthy for providing novel and powerful means of synthesis; they occur readily under mild conditions, give excellent yields of pure products, and, in contrast to SN2 displacements, are rather insensitive to steric hindrance. They are, therefore, especially valuable for the preparation of highly branched compounds. The view that these are electron-transfer chain processes derives from inhibition studies and, also, from the fact that these reactions are induced by one-electron-transfer agents.
Regiochemistry of the Association Step in SRN1 Reactions; Kinetically Controlled Coupling of aci-Nitronate Ions and p-Nitrobenzylic Radicals
Norris, Robert K.,Randles, David
, p. 1047 - 1051 (2007/10/02)
The regiochemistry of the coupling between p-nitrobenzylic radicals and aci-nitronate ions in the association step of SRN1 reactions is shown to be dependent on steric factors.Branching at the carbon which is α to the reaction site causes a shi
