lithium N-methylephedrate | 132350-99-3

• 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: lithium N-methylephedrate
• 英文别名: lithium (1R,2S)-N-methylephedrate；lithium;(1R,2S)-2-(dimethylamino)-1-phenylpropan-1-olate
• CAS: 132350-99-3
• 化学式: C₁₁H₁₆NO*Li
• 分子量: 185.195
• InChiKey: PLEKDFUNWZRECJ-ROLPUNSJSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -1.96
• 重原子数：
  14.0
• 可旋转键数：
  3.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.45
• 拓扑面积：
  26.3
• 氢给体数：
  0.0
• 氢受体数：
  2.0

反应信息

• 作为反应物：
  描述：

  lithium N-methylephedrate 、 <6Li,15N>-lithium hexamethyldisilazide dimer 以 氘代甲苯 为溶剂， 生成
  参考文献：
  名称：

  Solution Structures of Lithium Amino Alkoxides Used in Highly Enantioselective 1,2-Additions

  摘要：

  Lithium ephedrates and norcarane-derived lithium amino alkoxides used to effect highly enantioselective 1,2-additions on large scales have been characterized in toluene and tetrahydrofuran. The method of continuous variations in conjunction with Li-6 NMR spectroscopy reveals that the lithium amino alkoxides are tetrameric. In each case, low-temperature Li-6 NMR spectra show stereoisomerically pure homoaggregates displaying resonances consistent with an S-4-symmetric cubic core rather than the alternative D-2d core. These assignments are supported by density functional theory computations and conform to X-ray crystal structures. Slow aggregate exchanges are discussed in the context of amino alkoxides as chiral auxiliaries.

  DOI：

  10.1021/ja412210d
• 作为产物：
  描述：

  N-甲基麻黄碱 在 正丁基锂 作用下， 以 hexanes 、 甲苯 为溶剂， 生成 lithium N-methylephedrate
  参考文献：
  名称：

  Intermediates for the synthesis of polypropionate antibiotics

  摘要：

  这项发明涉及公式中的中间化合物 其中R1为H或保护基团，R2和R3分别独立地代表H、甲基或脱离基团，但要求R2和R3中至少有一个而不是两个是脱离基团。这些中间化合物可用于合成discodermolide、其衍生物和相关化合物。

  公开号：

  US07297807B1
• 作为试剂：
  描述：

  (2S,3R,5S,6S,7E)-1-tert-butyldiphenylsilyloxy-8-iodo-3,5-isopropilidendioxy-2,6-dimethyl-7-nonene 在 叔丁基锂 、 zinc dibromide 、 (2R,3R,5S)-5,7-di-tert-butyldimethylsilyloxy-2,4,4-trimethyl-3-triethylsilyloxyheptanal 、 lithium N-methylephedrate 作用下， 以 乙醚 为溶剂， 生成
  参考文献：
  名称：

  泰达内酯C合成的研究。C13-表位C1-C15片段的构建†

  摘要：

  此处报道了在合成他丹内酯C的过程中制备高级中间体的过程。它基于两个相似大小和复杂性的片段的偶联，而这些片段又是通过手性酮的高度立体选择性底物控制的钛介导的羟醛反应制备的。

  DOI：

  10.1039/c6ob00896h

文献信息

• Chelation of 2-substituted 1-lithoxides: structural and energetic factors of relevance to synthetic organic chemistry
  作者：Michael A. Nichols、Andrew T. McPhail、Edward M. Arnett

  DOI：10.1021/ja00016a045

  日期：1991.7

  A number of lithium 2-(methylamino)-, 2-(dimethylamino)-, 2-methoxy-, and 2-(isopropylthio)-substituted-1-phenyl-1-propoxides were studied as models for asymmetric synthetic strategies for which lithium chelation between two electronegative atoms has frequently been invoked. The heats of formation of these alkoxides were determined by deprotonating the alcohols with lithium bis(trimethylsilyl)amide in a solution calorimeter. Aggregation numbers for the substituted alcohols and their corresponding lithium alkoxides were obtained with freezing point depression and vapor pressure osmometry in THF, benzene, and dioxane. In several cases, solution structures were obtained through H-1, Li-6, and 2D Li-6-H-1 NOE (HOESY) NMR spectroscopy. Solid-state structures of lithium (+)-N-methylpseudoephedrate and (-)-N-methylephedrate (+)-N-methylpseudoephedrate and (-)-N-methylephedrate (as the benzene solvate) were obtained by X-ray crystallography, and both were found to be present as tetramers in which the dimethylamino nitrogen atoms were coordinated to the lithium cations to form five-membered chelate rings. The lithium alkoxides were either tetramers or hexamers in nonpolar solvents; however, the alkoxides' solution structures were very complex in THF as evidenced by several Li-6 resonances observed in the Li-6 NMR spectra at low temperatures. Intramolecular lithium chelation was found to occur in each alkoxide in dioxane and benzene. The enthalpies of chelational stabilization were estimated by comparing their heats of deprotonation with those of nonchelatable 2-alkyl-substituted analogues. The stabilization enthalpies ranged from 5 to 11 kcal/mol per alkoxide molecule.