Displacement of the nitro group of substituted nitrobenzenes-a synthetically useful process

Thermodynamic Study of σH Complexes in Nucleophilic Aromatic Substitution Reactions: Relative Stabilities of Electrochemically Generated Radicals

“…An oxidative nitro group substitution in 1,3-DNB and TNB by SEt -occurs with preparative yields that range from modest to good when a huge excess of the nucleophile is used. The nucleophilic displacement of a nitro group activated by ortho or para functions other than nitro groups has been demonstrated in the chemical literature, [15] but only a few synthetically useful S N Ar reactions involving the displacement of the NO 2 group in 1,3-DNB have been reported. [15] These results led us to ask why the same type of σ H complexes yield different substitution products, and consequently the different electrochemical oxidation pathways.…”

“…The nucleophilic displacement of a nitro group activated by ortho or para functions other than nitro groups has been demonstrated in the chemical literature, [15] but only a few synthetically useful S N Ar reactions involving the displacement of the NO 2 group in 1,3-DNB have been reported. [15] These results led us to ask why the same type of σ H complexes yield different substitution products, and consequently the different electrochemical oxidation pathways. This should be strongly connected to the ability of the substituent as a leaving group and to the bond dissociation energies (BDEs) of the corresponding C-Nu or C-H bond.…”

“…Hence, the standard potential for the oxidation of F -, E°F· /F -,DMF at 298 K, is estimated to be between 2.59 and 2.62 V from the available values of the free energy of transfer from water to DMF. [15,24] Clearly, this major uncertainty affects the use of the aforementioned thermodynamic cycles in estimating which process will operate in these cases. electrochemical oxidation of σ X complexes (the NASX mechanism).…”

Aromatic nucleophilic substitution. Part 2. Preparation of novel 3‐substituted xanthone and thioxanthone derivatives

“…The nitro groups in 4-nitrobenzophenone and 1-and 3-nitroxanthone were substituted by alkoxides [7]. Other nucleophilic substitutions with 4-nitrobenzophenone were also reported [8] [9]. We have now extended these reactions to the above-mentioned 3-nitro-9-oxo-9H-thioxanthenecarboxylic-acid derivatives.…”

Synthesis and characterization of new thermally stable poly(ether-imide)s derived from 4-aryl-2,6-bis[4-(3-nitrophthalimido)phenyl] pyridines

“…Most of the ether linkage formations employ halides, particularly fluoride, and nitro groups as a leaving group. Nitro groups are not frequently used as leaving groups due to the side-reactions of generated nitrite ions at elevated temperatures [33,34]. Nevertheless, the nitro-displacement reaction has been successfully utilized for the synthesis of many ether containing polymers [28,29,35,36].…”