p-methoxybenzoate(1-) | 1335-08-6

• 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: p-methoxybenzoate(1-)
• 英文别名: 4-Methoxybenzoate
• CAS: 1335-08-6
• 化学式: C₈H₇O₃
• 分子量: 151.142
• InChiKey: ZEYHEAKUIGZSGI-UHFFFAOYSA-M

物化性质

• LogP：
  1.960 (est)

计算性质

• 辛醇/水分配系数(LogP)：
  2.6
• 重原子数：
  11
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.12
• 拓扑面积：
  49.4
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  p-methoxybenzoate(1-) 以 甲醇 为溶剂， 生成 大茴香酸
  参考文献：
  名称：

  Ka Values of Weak Organic Acids in Protic Solvents Obtained from Their First Hyperpolarizabilities in Solution

  摘要：

  The first hyperpolarizabilities (beta) of some weak aromatic organic acids have been measured in protic solvents by the hyper-Rayleigh scattering (HRS) technique at low concentrations. The measured hyperpolarizability (beta(m)) varies between the two extreme limits: the hyperpolarizability of the acid form (beta(HA)) at the lower side and that of the basic form (beta(A-)) at the higher side. The degree of dissociation (alpha) of the acid in a solvent is related to the measured hyperpolarizability, beta(m), by the following relationship: beta(m)(2)=(1-alpha)beta(HA)(2)+alpha beta(A-)(2). The calculated beta's including solvent effects in terms of an Onsager field do not reproduce the experimentally measured hyperpolarizabilities. Other solvent-induced effects like hydrogen bonding and van der Waals interactions seem to influence the first hyperpolarizability and, thus, indirectly the extent of dissociation of these weak acids in these protic solvents.

  DOI：

  10.1021/j100051a014
• 作为产物：
  描述：

  大茴香酸 以 甲醇 为溶剂， 生成 p-methoxybenzoate(1-)
  参考文献：
  名称：

  Ka Values of Weak Organic Acids in Protic Solvents Obtained from Their First Hyperpolarizabilities in Solution

  摘要：

  The first hyperpolarizabilities (beta) of some weak aromatic organic acids have been measured in protic solvents by the hyper-Rayleigh scattering (HRS) technique at low concentrations. The measured hyperpolarizability (beta(m)) varies between the two extreme limits: the hyperpolarizability of the acid form (beta(HA)) at the lower side and that of the basic form (beta(A-)) at the higher side. The degree of dissociation (alpha) of the acid in a solvent is related to the measured hyperpolarizability, beta(m), by the following relationship: beta(m)(2)=(1-alpha)beta(HA)(2)+alpha beta(A-)(2). The calculated beta's including solvent effects in terms of an Onsager field do not reproduce the experimentally measured hyperpolarizabilities. Other solvent-induced effects like hydrogen bonding and van der Waals interactions seem to influence the first hyperpolarizability and, thus, indirectly the extent of dissociation of these weak acids in these protic solvents.

  DOI：

  10.1021/j100051a014

文献信息

• Enhanced reactivity of twisted amides inside a molecular cage
  作者：Hiroki Takezawa、Kosuke Shitozawa、Makoto Fujita

  DOI：10.1038/s41557-020-0455-y

  日期：2020.6

  When an amide group is distorted from its planar conformation, the conjugation between the nitrogen lone pair and the π* orbital of the carbonyl is disrupted and the reactivity towards nucleophiles is enhanced. Although there are several reports on the synthesis of activated twisted amides, amide activation through mechanical twisting is much less common. Here, we report twisted amides that are stabilized

  当酰胺基团的平面构象变形时，氮孤对与羰基的π*轨道之间的共轭被破坏，对亲核试剂的反应性增强。尽管有关于活化的扭曲酰胺的合成的报道，但通过机械扭曲进行酰胺活化的情况要少得多。在这里，我们报告了扭曲的酰胺，这些酰胺通过包含在自组装的配位笼中而得以稳定。当Td对称笼中包含仲芳族酰胺时，顺式-扭曲构型比跨平面构型更受青睐-单晶X射线衍射分析证明-酰胺可扭曲高达34° 。由于这种变形的结果，酰胺的水解在被包含时被显着加速。
• Competitive endo- and exo-cyclic C–N fission in the hydrolysis of <i>N</i>-aroyl β-lactams
  作者：Wing Y Tsang、Naveed Ahmed、Karl Hemming、Michael I Page

  DOI：10.1139/v05-153

  日期：2005.9.1

  The balance between endo- and exo-cyclic C–N fission in the hydrolysis of N-aroyl β-lactams shows that the difference in reactivity between strained β-lactams and their acyclic analogues is minimal. Attack of hydroxide ion occurs preferentially at the exocyclic acyl centre rather than that of the β-lactam during the hydrolysis of N-p-nitrobenzoyl β-lactam. In general, both endo- and exo-cyclic C–N bond fission occurs in the alkaline hydrolysis of N-aroyl β-lactams, the ratio of which varies with the aryl substituent. Hence, the Brønsted β-values differ for the two processes: –0.55 for the ring-opening reaction and –1.54 for the exocyclic C–N bond fission reaction. For the pH-independent and acid-catalysed hydrolysis of N-benzoyl β-lactam, less than 3% of products are derived from exocyclic C–N bond fission. Key words: β-lactams, hydrolysis, linear free energy relationships, strain.

  在N-酰基β-内酰胺水解中，内环和外环C-N裂解之间的平衡表明，受应变β-内酰胺和它们的非环结构类似物之间的反应性差异是最小的。在N-p-硝基苯甲酰基β-内酰胺水解过程中，羟根离子的攻击优先发生在外环酰基中心而不是β-内酰胺中心。一般来说，在N-酰基β-内酰胺的碱性水解中，内环和外环C-N键裂解都会发生，其比例随芳基取代基而变化。因此，这两个过程的Brønsted β值不同：环开启反应为-0.55，外环C-N键裂解反应为-1.54。对于N-苯甲酰基β-内酰胺的pH无关和酸催化水解，少于3%的产物来自外环C-N键裂解。关键词：β-内酰胺，水解，线性自由能关系，应变。
• Kinetics and Mechanism of the Basic Hydrolysis of Indomethacin and Related Compounds: A Reevaluation
  作者：Antonio Cipiciani、Cynthia Ebert、Paolo Linda、Fulvio Rubessa、Gianfranco Savelli

  DOI：10.1002/jps.2600720928

  日期：1983.9

  The kinetics of the hydrolysis of indomethacin and related compounds were studied in an alkaline medium at 25 degrees. The pseudo-first-order rate constants were evaluated from log absorbance versus time plots in the ultraviolet. These compounds showed a second-order rate constant at low concentrations of hydroxide ion and a first-order rate constant at higher concentrations of hydroxide ion.

  在25度碱性介质中研究了消炎痛及其相关化合物的水解动力学。根据对数吸光度与时间图在紫外线下评估伪一级反应速率常数。这些化合物在低浓度的氢氧根离子下显示出二级速率常数，而在较高浓度的氢氧根离子下显示出一级速率常数。
• Unexpected Resistance to Base-Catalyzed Hydrolysis of Nitrogen Pyramidal Amides Based on the 7-Azabicyclic[2.2.1]heptane Scaffold
  作者：Diego Ocampo Gutiérrez de Velasco、Aoze Su、Luhan Zhai、Satowa Kinoshita、Yuko Otani、Tomohiko Ohwada

  DOI：10.3390/molecules23092363

  日期：——

  of the base-catalyzed hydrolysis of 7-azabicyclo[2.2.1]heptane amides, which show pyramidalization of the amide nitrogen atom, and we compare the kinetics of the base-catalyzed hydrolysis of the benzamides of 7-azabicyclo[2.2.1]heptane and related monocyclic compounds. Unexpectedly, non-planar amides based on the 7-azabicyclo[2.2.1]heptane scaffold were found to be resistant to base-catalyzed hydrolysis

  非平面酰胺通常是过渡结构，参与酰胺键的旋转和氮原子的转化，但是已经报道了一些最低限度的非平面酰胺。非平面酰胺通常对水或其他亲核试剂敏感，因此酰胺键容易断裂。在本文中，我们研究了7-氮杂双环[2.2.1]庚烷酰胺的碱催化水解反应的反应性，该反应表明酰胺氮原子呈锥体反应，并且比较了碱催化苯甲酰胺水解的动力学。 7-氮杂双环[2.2.1]庚烷和相关的单环化合物。出乎意料的是，发现基于7-氮杂双环[2.2.1]庚烷骨架的非平面酰胺对碱催化的水解具有抵抗力。计算的吉布斯自由能与该实验结果一致。热校正的贡献（熵项，⁻TΔS‡）很大；熵项（ΔS‡）取大的负值，表明过渡结构中的重要顺序包括溶剂化水分子。
• Selective Enzymatic Transformation to Aldehydes<i>in vivo</i>by Fungal Carboxylate Reductase from<i>Neurospora crassa</i>
  作者：Daniel Schwendenwein、Giuseppe Fiume、Hansjörg Weber、Florian Rudroff、Margit Winkler

  DOI：10.1002/adsc.201600914

  日期：2016.11.3

  with only a handful of biocatalysts available to this end. We have increased the spectrum of carboxylate-reducing enzymes (CARs) with the sequence of a fungal CAR from Neurospora crassa OR74A (NcCAR). NcCAR was efficiently expressed in E. coli using an autoinduction protocol at low temperature. It was purified and characterized in vitro, revealing a broad substrate acceptance, a pH optimum at pH 5.5-6

  羧酸的酶促还原还处于初期，只有少数几种生物催化剂可用于此目的。我们已经利用来自神经孢霉OR74A（NcCAR）的真菌CAR的序列增加了羧酸盐还原酶（CARs）的谱图。NcCAR在低温下使用自动诱导方案在大肠杆菌中有效表达。对其进行了纯化和体外表征，显示了广泛的底物接受性，最适pH值为5.5-6.0，Tm为45°C和副产物焦磷酸盐的抑制作用（可通过添加焦磷酸酶来缓解）。NcCAR的合成效用已在使用大肠杆菌K-12 MG1655 RARE菌株进行全细胞生物转化中得到证实，目的是抑制过度还原为不想要的酒精。由戊酸（30 mM）以克规模制备芳香化合物胡椒醛，分离出的产率为92％，纯度> 98％。这对应于1.5g / L / h的生产率。