methyl {[p-methyl-alpha-(nitromethyl)benzyl]thio}acetate | 110113-20-7

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: methyl {[p-methyl-alpha-(nitromethyl)benzyl]thio}acetate
• 英文别名: Methyl 2-[1-(4-methylphenyl)-2-nitroethyl]sulfanylacetate
• CAS: 110113-20-7
• 化学式: C₁₂H₁₅NO₄S
• 分子量: 269.321
• InChiKey: CCARQCAQLZIKPX-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.5
• 重原子数：
  18
• 可旋转键数：
  6
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.42
• 拓扑面积：
  97.4
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为产物：
  描述：

  在 溶剂黄146 作用下， 以 水 、 乙腈 为溶剂， 生成 4-methyl-β-nitrostyrene 、 methyl mercaptoacetate 、 methyl {[p-methyl-alpha-(nitromethyl)benzyl]thio}acetate
  参考文献：
  名称：

  Kinetics of reversible thiolate ion addition to substituted .beta.-nitrostyrenes in water. Radicaloid transition state or principle of nonperfect synchronization?

  摘要：

  The kinetics of reversible nucleophilic thiolate ion (RS- with R = n-Bu, HOCH2CH2, MeO2CCH2CH2 and MeO2CCH2) addition to Z-substituted beta-nitrostyrenes (Z = 4-Me2N, 4-MeO, 4-MeS, 4-Me, H, 3-Cl, 4-Cl, 3-CN, 4-CN, and 3-NO2), to form ArCH(RS)CH = NO2-, have been measured in water at 20-degrees-C. Rate constants in the forward (k1) and reverse direction (k-1) and equilibrium constants (K1) correlate reasonably well with Hammett sigma-constants for the non-pi-donor substituents but show deviations for the pi-donors 4-Me2N, 4-MeO, and 4-MeS. These deviations are negative for K1 but positive for k1 and k-1; the positive deviations for the pi-donor substituents are also observed when plotting log k1 vs log K1 (Bronsted plots). The negative deviations of K1 are a consequence of resonance stabilization of the olefin. The positive deviations are attributed to a transition-state stabilization stemming from a preorganization created by the pi-donor which leads to a better delocalization of the negative charge into the nitro group. An alternative interpretation of the rate acceleration in terms of a radicaloid transition state (Gross, Z.; Hoz, S.J. Am. Chem. Soc. 1988, 110, 7489) cannot be ruled out but is shown to be less attractive and unnecessary. Bronsted parameters such as beta(nuc), beta(eq), beta(nuc)n, and beta(lg)n, and intrinsic rate constants (k(o) = k1 k-1 when K1 = 1) were determined from the dependence on RS- basicity for beta-nitrostyrene and 3-cyano-beta-nitrostyrene. Beta(eq) is low (0.5), indicating that the carbon basicity of RS- is less sensitive to electronic effects in R than its proton basicity. Beta(nuc) (beta(nuc)n) is very low, suggesting a transition state with very little C-S bond formation. The low beta(nuc)n (0.22) contrasts with a large alpha(nuc)n = d log k1/d log K1 = 0.74 (variation of Z), indicating a large transition-state imbalance (alpha(nuc)n - beta(nuc)n), as previously observed in the reaction of RS- with alpha-nitrostilbenes. The intrinsic rate constant (log k(o) = 3.5) is also similar to that for the reaction of RS- with alpha-nitrostilbenes and significantly higher than for the reaction of amines with beta-nitrostyrenes. Most of these features can, at least in part, be attributed to the soft acid-soft base interactions of RS- with the nitroolefins. Rate constants for carbon protonation of several of the ArCH(RS)CH = NO2- adducts by acetic acid (k(p)HA) were also determined. They display the unusual, but for nitronate ions typical, acceleration when Ar and/or R is made more electron withdrawing.

  DOI：

  10.1021/jo00034a032

文献信息

• Kinetics of reversible thiolate ion addition to substituted .beta.-nitrostyrenes in water. Radicaloid transition state or principle of nonperfect synchronization?
  作者：Claude F. Bernasconi、David F. Schuck

  DOI：10.1021/jo00034a032

  日期：1992.4

  The kinetics of reversible nucleophilic thiolate ion (RS- with R = n-Bu, HOCH2CH2, MeO2CCH2CH2 and MeO2CCH2) addition to Z-substituted beta-nitrostyrenes (Z = 4-Me2N, 4-MeO, 4-MeS, 4-Me, H, 3-Cl, 4-Cl, 3-CN, 4-CN, and 3-NO2), to form ArCH(RS)CH = NO2-, have been measured in water at 20-degrees-C. Rate constants in the forward (k1) and reverse direction (k-1) and equilibrium constants (K1) correlate reasonably well with Hammett sigma-constants for the non-pi-donor substituents but show deviations for the pi-donors 4-Me2N, 4-MeO, and 4-MeS. These deviations are negative for K1 but positive for k1 and k-1; the positive deviations for the pi-donor substituents are also observed when plotting log k1 vs log K1 (Bronsted plots). The negative deviations of K1 are a consequence of resonance stabilization of the olefin. The positive deviations are attributed to a transition-state stabilization stemming from a preorganization created by the pi-donor which leads to a better delocalization of the negative charge into the nitro group. An alternative interpretation of the rate acceleration in terms of a radicaloid transition state (Gross, Z.; Hoz, S.J. Am. Chem. Soc. 1988, 110, 7489) cannot be ruled out but is shown to be less attractive and unnecessary. Bronsted parameters such as beta(nuc), beta(eq), beta(nuc)n, and beta(lg)n, and intrinsic rate constants (k(o) = k1 k-1 when K1 = 1) were determined from the dependence on RS- basicity for beta-nitrostyrene and 3-cyano-beta-nitrostyrene. Beta(eq) is low (0.5), indicating that the carbon basicity of RS- is less sensitive to electronic effects in R than its proton basicity. Beta(nuc) (beta(nuc)n) is very low, suggesting a transition state with very little C-S bond formation. The low beta(nuc)n (0.22) contrasts with a large alpha(nuc)n = d log k1/d log K1 = 0.74 (variation of Z), indicating a large transition-state imbalance (alpha(nuc)n - beta(nuc)n), as previously observed in the reaction of RS- with alpha-nitrostilbenes. The intrinsic rate constant (log k(o) = 3.5) is also similar to that for the reaction of RS- with alpha-nitrostilbenes and significantly higher than for the reaction of amines with beta-nitrostyrenes. Most of these features can, at least in part, be attributed to the soft acid-soft base interactions of RS- with the nitroolefins. Rate constants for carbon protonation of several of the ArCH(RS)CH = NO2- adducts by acetic acid (k(p)HA) were also determined. They display the unusual, but for nitronate ions typical, acceleration when Ar and/or R is made more electron withdrawing.