isobutyl (E)-2-(1-(2-hydroxyethyl)piperidin-2-ylidene)acetate | 1161502-61-9

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 哌啶类
• 英文名称: isobutyl (E)-2-(1-(2-hydroxyethyl)piperidin-2-ylidene)acetate
• 英文别名: 2-methylpropyl (2E)-2-[1-(2-hydroxyethyl)piperidin-2-ylidene]acetate
• CAS: 1161502-61-9
• 化学式: C₁₃H₂₃NO₃
• 分子量: 241.331
• InChiKey: ORWGPQSCNOQBGF-FMIVXFBMSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.9
• 重原子数：
  17
• 可旋转键数：
  6
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.77
• 拓扑面积：
  49.8
• 氢给体数：
  1
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  isobutyl 7-chlorohept-2-ynoate 、 C.I.酸性橙108 以 乙腈 为溶剂， 反应 8.0h， 以65%的产率得到isobutyl (E)-2-(1-(2-hydroxyethyl)piperidin-2-ylidene)acetate
  参考文献：
  名称：

  Comparison of amine-induced cyclization of 6-chloro-1-hexynylphosphonate and isobutyl 7-chlorohept-2-ynoate

  摘要：

  The reaction of 6-chloro-1-hexynylphosphonate with primary and secondary amines afforded exclusively 2-aminocyclohexenylphosphonates in 62-85% isolated yields. In contrast, reaction of various amines with isobutyl 7-chlorohept-2-ynoate in acetonitrile at 70 degrees C gave (E)-sec-butyl 2-(1-alkylpiperidin-2-ylidene)acetates in 65-78% isolated yields. Calculations offer ail explanation for the difference in the behavior of the two compounds classes. It is shown that C-C cyclization in the alkyne-phosphonate group occurs via an initial formation of a zwitterionic intermediate, which is stabilized by both an inductive effect of the phosphonate group and a newly formed hydrogen bond. The alkyne-carboxylate group, on the other hand, proceeds via enamine formation as a result of the smaller inductive effect of the carboxylate combined with involvement of an allene-like resonance form. This resonance form both delocalizes the negative charge in the zwitterionic intermediate making it to be less available for attack, and affects the geometry thus preventing formation of the stabilizing hydrogen bond. Hence, the zwitterionic intermediate of the alkyne-carboxylates is less stable leading to formation of an enamine, which is followed by N-C cyclization to give the azaheterocycles. (C) 2009 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tet.2009.03.053

文献信息

• Comparison of amine-induced cyclization of 6-chloro-1-hexynylphosphonate and isobutyl 7-chlorohept-2-ynoate
  作者：Hemant Kumar Srivastava、Abed Al Aziz Quntar、Abdulatif Azab、Morris Srebnik、Avital Shurki

  DOI：10.1016/j.tet.2009.03.053

  日期：2009.5

  The reaction of 6-chloro-1-hexynylphosphonate with primary and secondary amines afforded exclusively 2-aminocyclohexenylphosphonates in 62-85% isolated yields. In contrast, reaction of various amines with isobutyl 7-chlorohept-2-ynoate in acetonitrile at 70 degrees C gave (E)-sec-butyl 2-(1-alkylpiperidin-2-ylidene)acetates in 65-78% isolated yields. Calculations offer ail explanation for the difference in the behavior of the two compounds classes. It is shown that C-C cyclization in the alkyne-phosphonate group occurs via an initial formation of a zwitterionic intermediate, which is stabilized by both an inductive effect of the phosphonate group and a newly formed hydrogen bond. The alkyne-carboxylate group, on the other hand, proceeds via enamine formation as a result of the smaller inductive effect of the carboxylate combined with involvement of an allene-like resonance form. This resonance form both delocalizes the negative charge in the zwitterionic intermediate making it to be less available for attack, and affects the geometry thus preventing formation of the stabilizing hydrogen bond. Hence, the zwitterionic intermediate of the alkyne-carboxylates is less stable leading to formation of an enamine, which is followed by N-C cyclization to give the azaheterocycles. (C) 2009 Elsevier Ltd. All rights reserved.