| 862604-51-1

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯酚醚
• CAS: 862604-51-1
• 化学式: C₂₈H₄₂O₂Sn
• 分子量: 529.35
• InChiKey: RERXVIOHBODHLL-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  8.63
• 重原子数：
  31
• 可旋转键数：
  6
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  18.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为产物：
  描述：

  1-methoxy-2-((4-methoxyphenyl)ethynyl)benzene 、 三正丁基氢锡 在 bis-triphenylphosphine-palladium(II) chloride 作用下， 以 甲苯 为溶剂， 生成 、
  参考文献：
  名称：

  Can Polarization of Triple Bond in Tolanes Be Deduced from ¹³C NMR Shifts? Re-evaluation of Factors Affecting Regiochemistry of the Palladium-Catalyzed Hydrostannation of Alkynes

  摘要：

  Polarization of the triple bond in a series of differently substituted ortho- and para-tolanes has been studied by NMR and computational methods in order to examine if C-13 NMR data can be effectively used for the assessment of electronic polarization of a triple bond in diarylacetylenes. DFT calculations of both natural charges and NMR properties revealed that chemical shifts concur with effective charges on sp-carbon atoms in para-tolanes, whereas in ortho-analogues magnetic anisotropy complicates the analysis making C-13 NMR data inapplicable for ascribing triple bond polarization. The obtained information was used to reevaluate factors affecting the regiochemistry of the Pd-catalyzed hydrostannation of the triple bond in tolanes. Computational study on the polarization of triple bonds taken together with the experimental data on hydrostannation of various mono- and disubstituted tolanes bearing para- and ortho-substituents demonstrated that the regioselectivity of hydrostannation is governed by a combination of electronic and steric factors. In para-tolanes, the electronic effect prevails and alpha- and beta-vinylstannanes are obtained predominantly for substrates with electron-withdrawing and electron-donating groups, respectively. In the ortho-series, steric factors dominate over electronics and a-isomers are produced with high selectivity regardless of the substituents' nature. However, it was found that in disubstituted "push-pull" tolanes steric control of an ortho-group can be overruled by the very strong electronic effect of an electron-withdrawing substituent in para-position.

  DOI：

  10.1021/ja051274v

文献信息

• Can Polarization of Triple Bond in Tolanes Be Deduced from ¹³C NMR Shifts? Re-evaluation of Factors Affecting Regiochemistry of the Palladium-Catalyzed Hydrostannation of Alkynes
  作者：Michael Rubin、Alexander Trofimov、Vladimir Gevorgyan

  DOI：10.1021/ja051274v

  日期：2005.7.1

  Polarization of the triple bond in a series of differently substituted ortho- and para-tolanes has been studied by NMR and computational methods in order to examine if C-13 NMR data can be effectively used for the assessment of electronic polarization of a triple bond in diarylacetylenes. DFT calculations of both natural charges and NMR properties revealed that chemical shifts concur with effective charges on sp-carbon atoms in para-tolanes, whereas in ortho-analogues magnetic anisotropy complicates the analysis making C-13 NMR data inapplicable for ascribing triple bond polarization. The obtained information was used to reevaluate factors affecting the regiochemistry of the Pd-catalyzed hydrostannation of the triple bond in tolanes. Computational study on the polarization of triple bonds taken together with the experimental data on hydrostannation of various mono- and disubstituted tolanes bearing para- and ortho-substituents demonstrated that the regioselectivity of hydrostannation is governed by a combination of electronic and steric factors. In para-tolanes, the electronic effect prevails and alpha- and beta-vinylstannanes are obtained predominantly for substrates with electron-withdrawing and electron-donating groups, respectively. In the ortho-series, steric factors dominate over electronics and a-isomers are produced with high selectivity regardless of the substituents' nature. However, it was found that in disubstituted "push-pull" tolanes steric control of an ortho-group can be overruled by the very strong electronic effect of an electron-withdrawing substituent in para-position.