8-methoxy-2-methylchromene | 127636-22-0

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 苯并吡喃
• 英文名称: 8-methoxy-2-methylchromene
• 英文别名: (r,s)-8-Methoxy-2-methyl-2h-chromene；8-methoxy-2-methyl-2H-chromene
• CAS: 127636-22-0
• 化学式: C₁₁H₁₂O₂
• 分子量: 176.215
• InChiKey: QEKDKLMJHMDUAX-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.6
• 重原子数：
  13
• 可旋转键数：
  1
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.27
• 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：

  邻香草醛 在 bis-triphenylphosphine-palladium(II) chloride 、 三苯基膦 、 lithium chloride 2,4,6-三甲基吡啶 、 2,6-二叔丁基-4-甲基苯酚 作用下， 以 二氯甲烷 、 N,N-二甲基甲酰胺 为溶剂， 反应 6.0h， 生成 8-methoxy-2-methylchromene
  参考文献：
  名称：

  Palladium-catalyzed cross-coupling reactions of highly hindered, electron-rich phenol triflates and organostannanes

  摘要：

  The palladium-catalyzed cross-coupling reaction of highly hindered, electron-rich phenol triflates and organostannanes (Stille reaction) has been studied in a systematic manner. The following are its salient features: (1) electron-rich phenol triflates require triphenylphosphine to undergo palladium-catalyzed cross-couplings; (2) in general, efficient reactions take place only when larger-than-usual amounts (10-15%) of palladium are employed. On the reagent side, alkyl- (methyl only), allyl-, vinyl- and alkinylstannanes undergo efficient cross-couplings with the title substrates. However, some limitations to this novel entry to 2-substituted resorcinols exist in regard to both substrates and reagents. Thus, conformationally rigid (hexasubstituted) aryl triflates behave poorly, demethylation being an important side reaction. Moreover, alkyl groups other than methyl cannot be introduced because beta-elimination occurs more rapidly. The potentially powerful synthesis of hindered biaryls has also been studied briefly. In the present conditions, the reaction appears to be limited by the presence of ortho substituents on the arylstannane moiety.

  DOI：

  10.1021/jo00028a051

文献信息

• Syntheses of Chromenes and Azachromenes: 2<i>H</i>-1-Benzopyran, 2<i>H</i>-Pyrano[3,2-<i>b</i>]pyridine, 2<i>H</i>-Pyrano[2,3-<i>c</i>]pyridine, and Derivatives
  作者：Dominique Billeret、Dominique Blondeau、Henri Sliwa

  DOI：10.1055/s-1993-25962

  日期：——

  2H-1-Benzopyran and derivatives have been prepared by an intramolecular Wittig reaction in a heterogeneous medium starting from salicylaldehyde, (2-hydroxyalkyl)triphenylphosphonium salts, and potassium carbonate. Extension of this reaction to various o-hydroxyformylpyridines were performed in order to obtain 2H-pyrano[3,2-b]pyridine, 2H-pyrano[2, 3-c]pyridine, and derivatives.

  2H-1-Benzopyran 及其衍生物是由水杨醛、（2-羟基烷基）三苯基鏻盐和碳酸钾在异相介质中通过分子内 Wittig 反应制备的。将该反应扩展到各种邻羟基甲酰基吡啶，从而得到 2H-吡喃并[3,2-b]吡啶、2H-吡喃并[2,3-c]吡啶及其衍生物。
• Palladium-catalyzed cross-coupling reactions of highly hindered, electron-rich phenol triflates and organostannanes
  作者：Jose M. Saa、Gabriel Martorell、Angel Garcia-Raso

  DOI：10.1021/jo00028a051

  日期：1992.1

  The palladium-catalyzed cross-coupling reaction of highly hindered, electron-rich phenol triflates and organostannanes (Stille reaction) has been studied in a systematic manner. The following are its salient features: (1) electron-rich phenol triflates require triphenylphosphine to undergo palladium-catalyzed cross-couplings; (2) in general, efficient reactions take place only when larger-than-usual amounts (10-15%) of palladium are employed. On the reagent side, alkyl- (methyl only), allyl-, vinyl- and alkinylstannanes undergo efficient cross-couplings with the title substrates. However, some limitations to this novel entry to 2-substituted resorcinols exist in regard to both substrates and reagents. Thus, conformationally rigid (hexasubstituted) aryl triflates behave poorly, demethylation being an important side reaction. Moreover, alkyl groups other than methyl cannot be introduced because beta-elimination occurs more rapidly. The potentially powerful synthesis of hindered biaryls has also been studied briefly. In the present conditions, the reaction appears to be limited by the presence of ortho substituents on the arylstannane moiety.