4,6-di-tert-butyl-3-(methoxycarbonyl)-2H-pyran-2-one | 76794-12-2

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡喃
• 英文名称: 4,6-di-tert-butyl-3-(methoxycarbonyl)-2H-pyran-2-one
• 英文别名: methyl 4,6-ditert-butyl-2-oxopyran-3-carboxylate
• CAS: 76794-12-2
• 化学式: C₁₅H₂₂O₄
• 分子量: 266.337
• InChiKey: WFZZNRYRUKPBIM-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.02
• 重原子数：
  19.0
• 可旋转键数：
  1.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.6
• 拓扑面积：
  56.51
• 氢给体数：
  0.0
• 氢受体数：
  4.0

反应信息

• 作为反应物：
  描述：

  4,6-di-tert-butyl-3-(methoxycarbonyl)-2H-pyran-2-one 以 1,4-二氧六环 为溶剂， 反应 4.3h， 生成 4,6-ditert-butyl-1H-pyridin-2-one
  参考文献：
  名称：

  Effects of Hindrance in N-Pyridyl Imidazolylidenes Coordinated to Iridium on Structure and Catalysis

  摘要：

  The unhindered N-pyrid-2-yl imidazolidene NHC ligand has been shown to chelate to a Cp*Ir fragment (1). With the goal of weakening the coordination of the pyridyl substituent and enabling its role as pendant base or hemilabile ligand, a tert-butyl group at C-6 next to the pyridyl N was installed. Attempted coordination of the newly synthesized carbene ligand avoided N-coordination entirely, but led to unexpected C-metalation at C-3 by the Cp*Ir center. Successful formation of a weakly N-coordinated analogue was achieved by synthesizing a ligand with a second tert-butyl group at C-4. The complexes were studied using X-ray crystallography and NMR spectroscopy. The X-ray crystal structure of di-tert-butyl analogue 6 showed that in the solid the complex existed as a chloride-bridged dimer, with the pyridyl nitrogen uncoordinated. In solution, N-15 chemical shift information revealed that 6 existed with the pyridyl substituent N-coordinated, presumably as a monomer, but that addition of an amine ligand readily opened the chelate. Finally, 6 was used as a catalyst for intramolecular hydroamination of primary and secondary alkenylamines. Comparing (heteroaryl)NHC species, each with a tert-butyl group next to the nitrogen, which enables hydroamination, the rate differences are very modest but increase in the order imidazolyl < pyridyl < pyrimidyl, which may be an effect of basicity but because of the similarity in rates is better ascribed to counterbalancing of more than one factor, including hemilability. The (4,6-di-tert-butyl)pyridyl species 6 was shown to be much more effective compared to parent compound 1 without the tert-butyl groups, in which the chelating group was more tightly bound.

  DOI：

  10.1021/om400758b
• 作为产物：
  描述：

  三甲基乙酰氯 在 bis-triphenylphosphine-palladium(II) chloride 、 copper(l) iodide 、 sodium methylate 、 三乙胺 作用下， 以 甲醇 为溶剂， 反应 28.0h， 生成 4,6-di-tert-butyl-3-(methoxycarbonyl)-2H-pyran-2-one
  参考文献：
  名称：

  Effects of Hindrance in N-Pyridyl Imidazolylidenes Coordinated to Iridium on Structure and Catalysis

  摘要：

  The unhindered N-pyrid-2-yl imidazolidene NHC ligand has been shown to chelate to a Cp*Ir fragment (1). With the goal of weakening the coordination of the pyridyl substituent and enabling its role as pendant base or hemilabile ligand, a tert-butyl group at C-6 next to the pyridyl N was installed. Attempted coordination of the newly synthesized carbene ligand avoided N-coordination entirely, but led to unexpected C-metalation at C-3 by the Cp*Ir center. Successful formation of a weakly N-coordinated analogue was achieved by synthesizing a ligand with a second tert-butyl group at C-4. The complexes were studied using X-ray crystallography and NMR spectroscopy. The X-ray crystal structure of di-tert-butyl analogue 6 showed that in the solid the complex existed as a chloride-bridged dimer, with the pyridyl nitrogen uncoordinated. In solution, N-15 chemical shift information revealed that 6 existed with the pyridyl substituent N-coordinated, presumably as a monomer, but that addition of an amine ligand readily opened the chelate. Finally, 6 was used as a catalyst for intramolecular hydroamination of primary and secondary alkenylamines. Comparing (heteroaryl)NHC species, each with a tert-butyl group next to the nitrogen, which enables hydroamination, the rate differences are very modest but increase in the order imidazolyl < pyridyl < pyrimidyl, which may be an effect of basicity but because of the similarity in rates is better ascribed to counterbalancing of more than one factor, including hemilability. The (4,6-di-tert-butyl)pyridyl species 6 was shown to be much more effective compared to parent compound 1 without the tert-butyl groups, in which the chelating group was more tightly bound.

  DOI：

  10.1021/om400758b

文献信息

• tert-Butyl-substituted cyclooctatetraenes
  作者：Michael J. Miller、Matthew H. Lyttle、Andrew Streitwieser

  DOI：10.1021/jo00323a001

  日期：1981.5
• MILLER M. J.; LYTTLE M. H.; STREITWIESER A., J. ORG. CHEM., 1981, 46, NO 10, 1977-1984
  作者：MILLER M. J.、 LYTTLE M. H.、 STREITWIESER A.

  DOI：——

  日期：——
• Effects of Hindrance in N-Pyridyl Imidazolylidenes Coordinated to Iridium on Structure and Catalysis
  作者：Zephen G. Specht、Douglas B. Grotjahn、Curtis E. Moore、Arnold L. Rheingold

  DOI：10.1021/om400758b

  日期：2013.11.11

  The unhindered N-pyrid-2-yl imidazolidene NHC ligand has been shown to chelate to a Cp*Ir fragment (1). With the goal of weakening the coordination of the pyridyl substituent and enabling its role as pendant base or hemilabile ligand, a tert-butyl group at C-6 next to the pyridyl N was installed. Attempted coordination of the newly synthesized carbene ligand avoided N-coordination entirely, but led to unexpected C-metalation at C-3 by the Cp*Ir center. Successful formation of a weakly N-coordinated analogue was achieved by synthesizing a ligand with a second tert-butyl group at C-4. The complexes were studied using X-ray crystallography and NMR spectroscopy. The X-ray crystal structure of di-tert-butyl analogue 6 showed that in the solid the complex existed as a chloride-bridged dimer, with the pyridyl nitrogen uncoordinated. In solution, N-15 chemical shift information revealed that 6 existed with the pyridyl substituent N-coordinated, presumably as a monomer, but that addition of an amine ligand readily opened the chelate. Finally, 6 was used as a catalyst for intramolecular hydroamination of primary and secondary alkenylamines. Comparing (heteroaryl)NHC species, each with a tert-butyl group next to the nitrogen, which enables hydroamination, the rate differences are very modest but increase in the order imidazolyl < pyridyl < pyrimidyl, which may be an effect of basicity but because of the similarity in rates is better ascribed to counterbalancing of more than one factor, including hemilability. The (4,6-di-tert-butyl)pyridyl species 6 was shown to be much more effective compared to parent compound 1 without the tert-butyl groups, in which the chelating group was more tightly bound.