| 239123-51-4

• CAS: 239123-51-4
• 化学式: C₁₅H₁₂O₅SW
• 分子量: 488.173
• InChiKey: JEKKCRNWJLXXGJ-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
  None
• 可旋转键数：
  None
• 环数：
  None
• sp3杂化的碳原子比例：
  None
• 拓扑面积：
  None
• 氢给体数：
  None
• 氢受体数：
  None

反应信息

• 作为反应物：
  描述：

  、 potassium hydroxide 在 potassium chloride 作用下， 以 水 、 乙腈 为溶剂， 生成
  参考文献：
  名称：

  Physical Organic Chemistry of Transition Metal Carbene Complexes. 21.¹ Kinetics and Mechanism of Hydrolysis of (CO)₅MC(SR)Ar (M = Cr and W; R = CH₃ and CH₃CH₂CH₂; Ar = C₆H₅ and 3-ClC₆H₄) in Aqueous Acetonitrile. Important Differences Relative to Complexes with Alkoxy Leaving Groups

  摘要：

  A kinetic study of the hydrolysis of (CO)(5)M=C(SMe)Ph (M = Cr and W) in 50% MeCN-50% water (v/v) at 25 degreesC over a pH range from 1.7 to 14.2 is reported. The reaction occurs in two stages: the first is formation of (CO)(5)M=C(O-)Ph or (CO)(5)M=C(OH)Ph while the second stage leads to the formation of PhCH=O and (CO)(5)MOH-. This paper is concerned with the first stage. The rate-pH profiles are complex and consistent with a mechanism (Scheme 1) that involves water/OH- addition to the substrate to form a tetrahedral intermediate (T-OH(-)), followed by product formation via five potential pathways whose relative importance depends on the pH. A more limited study of the reactions of (CO)(5)M=C(SCH2CH2CH3)Ph (M = Cr and W) and (CO)(5)M=C(SMe)C6H4-3-Cl (M = Cr and W) with OH- is also reported. The main focus of the discussion is aimed at understanding the reactivity differences between (CO)(5)M=C(SMe)Ph and the corresponding methoxy analogues studied earlier. This understanding is in large measure based on an analysis of how the intrinsic rate constants are affected by the interplay of steric, inductive, and pi -donor effects and the potential imbalances of these effects at the transition state. It is also shown that the much lower sensitivity to H+-catalysis of RS- compared to RO- leaving group departure from the tetrahedral intermediate is responsible for the more complex rate-pH profile for the hydrolysis of (CO)(5)M=C(SMe)Ph than for the hydrolysis of the methoxy analogue.

  DOI：

  10.1021/ja002371l
• 作为产物：
  描述：

  以 not given 为溶剂， 生成
  参考文献：
  名称：

  Physical Organic Chemistry of Transition Metal Carbene Complexes. 17.¹ Kinetics of the Reactions of (Arylthioalkoxycarbene)pentacarbonyl Complexes of Chromium(0) and Tungsten(0) with Thiolate Ions in Aqueous Acetonitrile:  pK_a Values of the Metal-Protonated Tetrahedral Adducts Formed between Carbene Complexes and Thiolate Ion

  摘要：

  Rate and equilibrium constants for the nucleophilic attachment of various thiolate ions to (CO)(5)M= C(SMe)Ph (M = Cr and W) and for the attachment of HOCH2CH2S- to (CO)(5)W=C(SCH2CH2OH)C(6)H(4)Z (Z = CF3, Cl, F, H, Me, MeO, and Me2N) have been determined in 50% MeCN-50% water (v/v) at 25 degrees C. For some of the adducts, those of the general structure (CO)(5)MC(SR,SR')C(6)H(4)Z, a kinetic determination of the pK(a) of their metal-protonated conjugate acid, (CO)(5)M(H)C(SR,SR')C(6)H(4)Z, is also reported. On the basis of Br phi nsted coefficients, Hammett rho values and comparisons with the reactions of the same thiolate ions with methoxy carbene complexes such as (CO)(5)M=C(OMe)Ph, insights into the role played by desolvation of the nucleophile prior to C-S bond formation, by the smaller pi-donor and inductive but larger steric effects of the MeS compared to the MeO group, by transition state imbalances, etc. are discussed. The pK(a) values obtained for (CO)(5)M(H)C(SR,SR')C(6)H(4)Z were used to resolve a mechanistic ambiguity in the hydrolysis of Fischer carbenes that have acidic protons on the alpha-carbon, e.g., (CO)(5)Cr=C(OMe)Me.

  DOI：

  10.1021/ja992741+

文献信息

• Physical Organic Chemistry of Transition Metal Carbene Complexes. 16.¹ Reactions of (CO)₅MC(OR)Ph (M = Cr or W; R = Me or Et) with Thiolate Ions in Aqueous Acetonitrile. Complete Kinetic Dissection of the Two-Step Mechanism
  作者：Claude F. Bernasconi、Kevin W. Kittredge、Francis X. Flores

  DOI：10.1021/ja9908265

  日期：1999.7.1

  high pH formation of a tetrahedral intermediate, (CO)5MC(OR‘)(SR)Ph, is observed. Upon addition of acid the intermediate is converted into the substitution product. For the reactions of most thiolate ions a detailed kinetic analysis allowed the determination of the rate constants for nucleophilic attack on the carbene complexes (k1) and its reverse (k-1), the equilibrium constant for nucleophilic addition

  (CO)5MC(OR')Ph 反应的动力学研究 (1a, M = Cr, R' = Me; 1b, M = W, R' = Me; 1c, M = Cr, R' = Et; 1d, M = W, R' = Et) 与 n-PrS-、HOCH2CH2S-、MeO2CCH2CH2S- 和 MeO2CCH2S- 在 50% MeCN-50% 水 (v/v) 中在 25 °C 报告。在低 [RS-] 和相对低的 pH 值下，反应会产生亲核取代产物 (CO)5MC(SR)Ph，而没有任何中间体的积累。在高 [RS-] 和高 pH 值下，观察到四面体中间体 (CO)5MC(OR')(SR)Ph 的形成。加入酸后，中间体转化为取代产物。对于大多数硫醇盐离子的反应，详细的动力学分析允许确定卡宾配合物上亲核攻击的速率常数 (k1) 及其反向 (k-1)，亲核加成的平衡常数 (K1 = k1/k- 1), 以及醇盐离子离开由