methoxycarbonyl cation

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: methoxycarbonyl cation
• 英文别名: Methoxymethanone
• 化学式: C₂H₃O₂
• 分子量: 59.0446
• InChiKey: DGZUOEYTSXYLSS-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1
• 重原子数：
  4
• 可旋转键数：
  0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  10.2
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  氘代苯 、 methoxycarbonyl cation 生成
  参考文献：
  名称：

  气相亲电子芳族取代中甲氧羰基阳离子的反应性和选择性

  摘要：

  Methoxycarbonyl cations, prepared in the gas phase from the dissociation of methyl chloroformate and trifluoromethyl acetate following charge transfer from ionized CO2 or Xe, were structurally characterized by collisional activation spectroscopy, and their reactivity toward aromatic substrates was investigated by mass spectrometric and radiolytic methods in the pressure range from 10(-7) to 720 Torr. Under ICR conditions, only fragments corresponding to protonated toluene and benzyl cations were obtained, with nearly unit collision efficiency, from the reaction with benzene, while methoxycarbonylated ionic addition products appeared in the CO2 chemical ionization spectra at 0.1 Torr and were analyzed by MIKE and CA spectroscopy. Electrophilic aromatic methoxycarbonylation was studied in radiolytic systems at atmospheric pressure by competition experiments, and the partial rate factors for substituted benzenes were measured. Independent of the precursor and the process used for the formation of the reagent, the reaction is characterized by a rho value of -1.5 typical of a rather unselective gaseous electrophile.

  DOI：

  10.1021/j100119a029

文献信息

• Gas-phase oxirane addition to acylium ions on reaction with 1,3-dioxolanes elucidated by tandem and triple stage mass spectrometric experiments
  作者：Marcos N. Eberlin、R. G. Cooks

  DOI：10.1002/oms.1210280605

  日期：1993.6

  AbstractAcylium ions containing a variety of substituents all undergo an unprecedented reaction with 1,3‐dioxolanes which gives rise to a cyclic, resonance‐stabilized oxonium ion, formally the product of oxirane (C2H4O) addition to the reagent ion. The structure for the ion–molecule product is supported by multiple‐stage mass spectrometric experiments, performed in a pentaquadrupole mass spectrometer, which show the expected fragmentation by C2H4O loss to yield the original reactant acylium ions. The oxonium ions are formed in relatively high abundance in many cases and are observed even when proton‐transfer reactions would be expected to occur competitively owing to the acidity of some of the acylium ions studied. This ion–molecule reaction is proposed to serve as a general method for identification and/or trapping of ions of the whole acylium ion class and also for the gas‐phase generation of the oxonium ions. The reaction with 1,3‐dioxolane is also useful in distinguishing the most stable C2H3O+ ion, the acetyl cation, from its two stable isomers, O‐protonated ketene and the oxiranyl cation. The thioacetyl cation, the only sulfur analog investigated, also reacts with dioxolane to form the corresponding oxirane addition product, indicating that the C2H4O addition reaction occurs and that it may be useful for identification of the thioacylium class and for the gas‐phase generation of sulfur analogs of oxonium ions.