3,5-bis((S)-4-isopropyl-4,5-dihydro-2-oxazolyl)-1H-pyrazole

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 唑类
• 英文名称: 3,5-bis((S)-4-isopropyl-4,5-dihydro-2-oxazolyl)-1H-pyrazole
• 英文别名: (4S)-4-propan-2-yl-2-[3-[(4S)-4-propan-2-yl-4,5-dihydro-1,3-oxazol-2-yl]-1H-pyrazol-5-yl]-4,5-dihydro-1,3-oxazole
• 化学式: C₁₅H₂₂N₄O₂
• 分子量: 290.365
• InChiKey: JFQRMEMAWYMEBW-CHWSQXEVSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.7
• 重原子数：
  21
• 可旋转键数：
  4
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.67
• 拓扑面积：
  71.9
• 氢给体数：
  1
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  氟硼酸铵 、 (2-methylallyl)palladium-chloride dimer 、 3,5-bis((S)-4-isopropyl-4,5-dihydro-2-oxazolyl)-1H-pyrazole 在 potassium tert-butoxide 作用下， 以 二氯甲烷 为溶剂， 以98%的产率得到bis(η3-methallyl)[3,5-bis((S)-4-isopropyl-4,5-dihydro-2-oxazolyl)-pyrazolate-N,N,N',N']dipalladium(II) tetrafluoroborate
  参考文献：
  名称：

  Dinuclear Allylpalladium Complexes ofC₂-Symmetric Pyrazolate-Bridged Bis(oxazoline) Ligands (pyrbox's): Structures, Dynamic Behavior, and Application in Asymmetric Allylic Alkylation

  摘要：

  A series of new chiral binucleating pyrazolate-based N-donor ligands (3a-d) with oxazoline side arms (coined pyrbox's) have been synthesized. Bimetallic methallylpalladium complexes (4a-d) of these ligands were obtained, and the solid-state structures of complexes 4a,c were characterized by X-ray diffraction. NMR spectroscopy revealed that in solution 4a-d exist as three different isomers that differ in the orientation of the two methallyl ligands. Exchange between the isomers (i.e., allyl rotation) was observed in two-dimensional NOESY NMR experiments as syn/syn and anti/anti interconversion of the allylic hydrogen atoms; kinetic parameters for the fluxional behavior have been determined. The catalytic activity of the complexes was tested in palladium-catalyzed allylic alkylation of rac-(E)-1,3-diphenylallyl acetate. By comparison of the set of complexes 4a-d that feature different ligand scaffolds, both steric and electronic factors were found to be important for enantiocontrol, and a model has been proposed for rationalizing the observed enantioselectivities.

  DOI：

  10.1021/om900835f
• 作为产物：
  描述：

  N3,N5-bis((S)-1-hydroxy-3-methylbutan-2-yl)-1H-pyrazole-3,5-dicarboxamide 在 氯化亚砜 、 sodium methylate 作用下， 以 1,2-二氯乙烷 、 甲醇 为溶剂， 反应 7.0h， 以62%的产率得到3,5-bis((S)-4-isopropyl-4,5-dihydro-2-oxazolyl)-1H-pyrazole
  参考文献：
  名称：

  Dinuclear Allylpalladium Complexes ofC₂-Symmetric Pyrazolate-Bridged Bis(oxazoline) Ligands (pyrbox's): Structures, Dynamic Behavior, and Application in Asymmetric Allylic Alkylation

  摘要：

  A series of new chiral binucleating pyrazolate-based N-donor ligands (3a-d) with oxazoline side arms (coined pyrbox's) have been synthesized. Bimetallic methallylpalladium complexes (4a-d) of these ligands were obtained, and the solid-state structures of complexes 4a,c were characterized by X-ray diffraction. NMR spectroscopy revealed that in solution 4a-d exist as three different isomers that differ in the orientation of the two methallyl ligands. Exchange between the isomers (i.e., allyl rotation) was observed in two-dimensional NOESY NMR experiments as syn/syn and anti/anti interconversion of the allylic hydrogen atoms; kinetic parameters for the fluxional behavior have been determined. The catalytic activity of the complexes was tested in palladium-catalyzed allylic alkylation of rac-(E)-1,3-diphenylallyl acetate. By comparison of the set of complexes 4a-d that feature different ligand scaffolds, both steric and electronic factors were found to be important for enantiocontrol, and a model has been proposed for rationalizing the observed enantioselectivities.

  DOI：

  10.1021/om900835f