The effect of acyl substituents on the α-effect: contrasting α-effect profiles for reactions of 4-nitrophenyl substituted benzoates with neutral and anionic nucleophiles

Um, Ik‐Hwan; Han, Hyun-Joo; Chung, Eun-Kyung

doi:10.1016/s0040-4039(01)01719-1

Cited by 4 publications

(1 citation statement)

References 19 publications

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“…Finally, most reactions examined in connection with the α-effect have been carried out in solution, and a considerable number of studies have been devoted to examine the effect of solvent on the reactivity of α-nucleophiles. ,− ,,,,,,,− These studies revealed that the magnitude of the α-effect depends on the solvent used. However, there is no clear evidence that the solvent plays an essential role in generating the α-effect, although the size of the effect appears to be modified by solvent.…”

Section: Introductionmentioning

confidence: 99%

The α-Effect in Gas-Phase S_N2 Reactions: Existence and the Origin of the Effect

Ren

Yamataka

2007

J. Org. Chem.

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The origin of enhanced reactivity of alpha-nucleophiles in SN2 reactions was examined on the basis of computational results at the high level G2(+) method for 22 gas-phase reactions: Nu- + RCl --> RNu + Cl- [R = Et and i-Pr; Nu- = HO-, CH3O-, HS-, Cl-, Br-, NH2O-, HOO-, FO-, HSO-, ClO-, and BrO-]. The results clearly indicate the existence of the alpha-effect, whose size varies depending on the R group and the identity of the alpha-atom. The alpha-effect is larger for i-PrCl than EtCl, and for an alpha-nucleophile with a harder alpha-atom. Analyses of the present results, together with previously reported ones for MeF and MeCl reactions, reveal that several rationales so far presented to explain the alpha-effect, such as thermodynamic product stability, transition state (TS) tightness, electrostatic interaction, ET rationale, and polarizability, cannot explain the observed size of the alpha-effect. The importance of deformation energy on going from the reactant to the TS is presented.

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Section: Introductionmentioning

confidence: 99%

The α-Effect in Gas-Phase S_N2 Reactions: Existence and the Origin of the Effect

Ren

Yamataka

2007

J. Org. Chem.

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The α-effect and its modulation by solvent

2004

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The electronic effects of substituents onⁿJ_PX(n = 2, 3; X = H, C) coupling constants and phosphorus chemical shifts; syntheses and spectroscopic investigation of some phosphoramidates

Gholivand¹,

Shariatinia‬²,

Tadjarodi³

2005

Main Group Chemistry

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New phosphoramidates with the general formulae Me 2 NP(O)Cl(p-NHC 6 H 4 -R) (A) and Me 2 NP(O)(p-NHC 6 H 4 -R) 2 (B), where R = H, CH 3 and NO 2 , F, Cl, Br, I, were synthesized and characterized by 1 H, 13 C, 31 P NMR and IR spectroscopy and elemental analysis. The electronic effects of donor, acceptor and neutral groups on n J PX coupling constants (n = 2, 3; X = H, C) and phosphorus chemical shifts are discussed. NMR data show that only the 4-nitroaniline substituent resulted in the disappearance of all coupling ( n J PX = 0.0 Hz). Two nearly linear correlations were obtained between para-substituent constants (s p ) and phosphorus chemical shifts for the two series A and B.

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The effect of acyl substituents on the α-effect: contrasting α-effect profiles for reactions of 4-nitrophenyl substituted benzoates with neutral and anionic nucleophiles

Cited by 4 publications

References 19 publications

The α-Effect in Gas-Phase S_N2 Reactions: Existence and the Origin of the Effect

The α-Effect in Gas-Phase S_N2 Reactions: Existence and the Origin of the Effect

The α-effect and its modulation by solvent

The electronic effects of substituents onⁿJ_PX(n = 2, 3; X = H, C) coupling constants and phosphorus chemical shifts; syntheses and spectroscopic investigation of some phosphoramidates

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The effect of acyl substituents on the α-effect: contrasting α-effect profiles for reactions of 4-nitrophenyl substituted benzoates with neutral and anionic nucleophiles

Cited by 4 publications

References 19 publications

The α-Effect in Gas-Phase SN2 Reactions: Existence and the Origin of the Effect

The α-Effect in Gas-Phase SN2 Reactions: Existence and the Origin of the Effect

The α-effect and its modulation by solvent

The electronic effects of substituents onnJPX(n = 2, 3; X = H, C) coupling constants and phosphorus chemical shifts; syntheses and spectroscopic investigation of some phosphoramidates

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Product

Resources

About

The α-Effect in Gas-Phase S_N2 Reactions: Existence and the Origin of the Effect

The α-Effect in Gas-Phase S_N2 Reactions: Existence and the Origin of the Effect

The electronic effects of substituents onⁿJ_PX(n = 2, 3; X = H, C) coupling constants and phosphorus chemical shifts; syntheses and spectroscopic investigation of some phosphoramidates