Rationalization of the conflicting effects of hydrogen bond donor solvent on nucleophilic aromatic substitution reactions in non-polar aprotic solvent: reactions of phenyl 2,4,6-trinitrophenyl ether with primary and secondary amines in benzene–methanol mixtures

Banjoko, Olayinka; Babatunde, Ibitola A.

doi:10.1016/j.tet.2004.03.079

Cited by 29 publications

(23 citation statements)

References 20 publications

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“…3,5 The reaction mechanism, reactivity, and solvents effects on these systems have been examined extensively. [6][7][8] We also have recently reported on the displacement reaction of strongly activated aromatic compounds by anilines and pyridines of chloride in MeOH-MeCN solvents. 9,10 These studies showed that the N-C bond forming step gave a great contribution to the overall second order rate constant.…”

Section: Introductionmentioning

confidence: 99%

Kinetics and Mechanism of Nucleophilic Substitution Reaction of 4-Substituted-2,6-dinitrochlorobenzene with Benzylamines in MeOH-MeCN Mixtures

Kim¹,

Choi²,

Yang³

et al. 2010

Bulletin of the Korean Chemical Society

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The reaction rates of 4-X-2,6-dinitrochlorobenzenes (X = NO2, CN, CF3) with Y-substituted benzylamines H, in MeOH-MeCN mixtures were measured by conductometry at 25 o C. It was observed that the rate constant increased in the order of X = NO2 > CN > CF3 and in the order of Y = p-OCH3 > p-CH3 > H > p-Cl. When the solvent composition was varied, the rate constant increased in the order of 100% MeOH < 50% (v/v) MeOH-MeCN < 100% MeCN. These results may be ascribed to the formation of hydrogen bonds between the alcoholic hydrogen and nitrogen of benzylamines in groud state (GS). We conclude that the reaction takes place via SNAr base on the transition state parameters ρX, ρY, βnuc, and solvent effects.

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Section: Introductionmentioning

confidence: 99%

Kinetics and Mechanism of Nucleophilic Substitution Reaction of 4-Substituted-2,6-dinitrochlorobenzene with Benzylamines in MeOH-MeCN Mixtures

Kim¹,

Choi²,

Yang³

et al. 2010

Bulletin of the Korean Chemical Society

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“…Examination of the literature revealed that the effects of structure on S N Ar2 reactions have largely been reported 9–23. However, only very few attempts have been made to study on the effect of solvent on such reactions in a more systematic manner 24–30. Hence, in this article, the reaction of few parasubsutituted anilines with 2‐bromo‐5‐nitropyridine and with 2‐chloro‐5‐nitropyridine in dimethylsulfoxide (DMSO)/acetonitrile (AcN) (both polar, aprotic, Hydrogen Bond Acceptor, PAHBA solvents) mixtures of varying compositions has been reported.…”

Section: Introductionmentioning

confidence: 99%

Solvent hydrogen bonding and structural effects on the reaction of 2‐halo‐5‐nitropyridines with parasubstituted anilines in dimethylsulfoxide/acetonitrile mixtures

Kalaimani¹,

Rathinam²,

Bhuvaneshwari³

2011

Int J of Chemical Kinetics

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Substitution reactions of some parasubstituted anilines with 2-chloro-5-nitropyridine and 2-bromo-5-nitropyridine were carried out conductometrically in dimethylsulfoxide/acetonitrile mixtures. The correlation of second order rate constants with Hammett's substituent constants yields a fairly linear straight line with a negative slope. The correlation of rate data with Kamlet-Taft's solvatochromic parameters is excellent (100R 2 = 97%) in both the substrates. The solvation model proposed is well supported by the solvatochromism exhibited by aniline in the solvent mixture under investigation. The molar extinction coefficient (ε max ) of aniline varies appreciably up to ∼25% with the change in composition of the mixture. The multivariate correlation analysis of ε max (with α, β, π *) suggests that the solvation around NH 2 moiety of aniline through hydrogen bond donor (HBD) property is found to be dominant in the solvation process and consequently in altering the rate. The observation is that the dominance of HBD property in solvation is further confirmed by the cyclic voltammetric oxidation of aniline in the solvent mixture. C

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“…6,7 But when there exists specific solvation between them, the rate is remarkably changed in the same solvent transfer. 6,8 Reaction mechanism, reactivity and solvents effects in these systems have been examined extensively [9][10][11] and we have recently studied the displacement reaction of strongly activated aromatic compounds by anilines of chloride in methanol-acetonitrile solvents. 12 This study showed that the N-C bond forming step made a great contribution to the overall second order rate constant.…”

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confidence: 99%

Kinetic Studies on the Nucleophilic Substitution Reaction of 4-X-Substituted-2,6-dinitrochlorobenzene with Pyridines in MeOH-MeCN Mixtures

Sung¹,

Choi²,

Lee³

et al. 2009

Bulletin of the Korean Chemical Society

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The reaction rates of 4-X-2,6-dinitrochlorobenzenes (X = NO2, CN, CF3) with Y-substituted pyridines (Y = 3-OCH3, H, 3-CH3, 4-CH3) in methanol-acetonitrile mixtures were measured by conductometry at 25 o C. It was observed that the rate constant increased in the order of X = 4-NO2 > 4-CN > 4-CF3 and the rate constant also increased in the order of Y = 4-CH3 > 3-CH3 > H > 3-OCH3. When the solvent composition was varied, the rate constant increased in order of MeCN > 50% MeOH > MeOH. The electrophilic catalysis by methanol may be ascribed to the formation of hydrogen bonds between alcoholic hydrogen and nitrogen of pyridines in ground state. Based on the transition parameters, ρS, ρN, β Y, ρXY and solvent effects, the reaction seems to proceed via SNAr-Ad.E mechanism. We also estimated the isokinetic solvent mixtures (ρXY = 0) based on cross-interaction constants, where the substituent effects of the substrate and nucleophile are compensated.

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Rationalization of the conflicting effects of hydrogen bond donor solvent on nucleophilic aromatic substitution reactions in non-polar aprotic solvent: reactions of phenyl 2,4,6-trinitrophenyl ether with primary and secondary amines in benzene–methanol mixtures

Cited by 29 publications

References 20 publications

Kinetics and Mechanism of Nucleophilic Substitution Reaction of 4-Substituted-2,6-dinitrochlorobenzene with Benzylamines in MeOH-MeCN Mixtures

Kinetics and Mechanism of Nucleophilic Substitution Reaction of 4-Substituted-2,6-dinitrochlorobenzene with Benzylamines in MeOH-MeCN Mixtures

Solvent hydrogen bonding and structural effects on the reaction of 2‐halo‐5‐nitropyridines with parasubstituted anilines in dimethylsulfoxide/acetonitrile mixtures

Kinetic Studies on the Nucleophilic Substitution Reaction of 4-X-Substituted-2,6-dinitrochlorobenzene with Pyridines in MeOH-MeCN Mixtures

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