methyl (2E)-2-[(5E)-5-[(4-methoxyphenyl)methylidene]oxolan-2-ylidene]acetate | 191329-60-9

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯酚醚
• 英文名称: methyl (2E)-2-[(5E)-5-[(4-methoxyphenyl)methylidene]oxolan-2-ylidene]acetate
• CAS: 191329-60-9
• 化学式: C₁₅H₁₆O₄
• 分子量: 260.29
• InChiKey: NLVIGCFYQAQEJJ-UTLPMFLDSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.6
• 重原子数：
  19
• 可旋转键数：
  4
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.27
• 拓扑面积：
  44.8
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  甲醇 、 methyl (2E)-2-[(5E)-5-[(4-methoxyphenyl)methylidene]oxolan-2-ylidene]acetate 在 sodium methylate 作用下， 以 四氢呋喃 为溶剂， 反应 24.0h， 以30%的产率得到methyl 3-methoxy-7-(4-methoxyphenyl)-6-oxohept-2-enoate
  参考文献：
  名称：

  Synthesis of 2,5-Disubstituted Furans via Palladium-Catalyzed Annulation of Alkyl 3-Oxo-6-heptynoates

  摘要：

  The reaction of the readily available alkyl 3-oxo-6-heptynoates with aryl halides in the presence of K2CO3 and catalytic amounts of Pd(PPh3)(4) at 100 degrees C provides a valuable new route to 2,5-disubstituted furans 3. Most probably, the furan ring is generated through an annulation reaction promoted by sigma-arylpalladium complexes generated in situ and involving the nucleophilic attack of the ketonic oxygen across the carbon-carbon triple bond coordinated to palladium, followed by the base-catalyzed isomerization of the resultant stereoisomeric 2,5-dialkylidenetetrahydrofuran intermediates 4 and 5. The reaction is highly chemoselective. No evidence was obtained of carboannulation products. The reaction temperature has proven to be crucial for the success of the methodology. The K2CO3:alkyne ratio also affects the reaction outcome. The highest yields of furan derivatives have been obtained with aryl halides containing electron-withdrawing substituents, very likely because the higher acidity of the methylene protons of 4 and 5 favors the isomerization step. Extension of the methodology to methyl 3-oxo-7-substituted-6-heptynoates leads to the formation of 2,5-disubstituted furans containing a branched side chain. The presence of an alkyl substituent on the C-2 of the staring alkyne, however, seems to prevent the isomerization step. Treatment of ethyl 2-methyl-3-oxo-6-heptynoate under our standard conditions produced in fact the 2,5-dialkylidene derivative 5p in 42% yield, and no evidence of the corresponding furan derivative was attained.

  DOI：

  10.1021/jo962386v
• 作为产物：
  描述：

  炔丙基脲 在 4-二甲氨基吡啶 、 四(三苯基膦)钯 、 potassium carbonate 、 N,N'-二环己基碳二亚胺 作用下， 以 二氯甲烷 、 N,N-二甲基甲酰胺 为溶剂， 反应 41.0h， 生成 methyl (2E)-2-[(5E)-5-[(4-methoxyphenyl)methylidene]oxolan-2-ylidene]acetate
  参考文献：
  名称：

  Synthesis of 2,5-Disubstituted Furans via Palladium-Catalyzed Annulation of Alkyl 3-Oxo-6-heptynoates

  摘要：

  The reaction of the readily available alkyl 3-oxo-6-heptynoates with aryl halides in the presence of K2CO3 and catalytic amounts of Pd(PPh3)(4) at 100 degrees C provides a valuable new route to 2,5-disubstituted furans 3. Most probably, the furan ring is generated through an annulation reaction promoted by sigma-arylpalladium complexes generated in situ and involving the nucleophilic attack of the ketonic oxygen across the carbon-carbon triple bond coordinated to palladium, followed by the base-catalyzed isomerization of the resultant stereoisomeric 2,5-dialkylidenetetrahydrofuran intermediates 4 and 5. The reaction is highly chemoselective. No evidence was obtained of carboannulation products. The reaction temperature has proven to be crucial for the success of the methodology. The K2CO3:alkyne ratio also affects the reaction outcome. The highest yields of furan derivatives have been obtained with aryl halides containing electron-withdrawing substituents, very likely because the higher acidity of the methylene protons of 4 and 5 favors the isomerization step. Extension of the methodology to methyl 3-oxo-7-substituted-6-heptynoates leads to the formation of 2,5-disubstituted furans containing a branched side chain. The presence of an alkyl substituent on the C-2 of the staring alkyne, however, seems to prevent the isomerization step. Treatment of ethyl 2-methyl-3-oxo-6-heptynoate under our standard conditions produced in fact the 2,5-dialkylidene derivative 5p in 42% yield, and no evidence of the corresponding furan derivative was attained.

  DOI：

  10.1021/jo962386v

文献信息

• Synthesis of 2,5-Disubstituted Furans via Palladium-Catalyzed Annulation of Alkyl 3-Oxo-6-heptynoates
  作者：Sandro Cacchi、Giancarlo Fabrizi、Leonardo Moro

  DOI：10.1021/jo962386v

  日期：1997.8.1

  The reaction of the readily available alkyl 3-oxo-6-heptynoates with aryl halides in the presence of K2CO3 and catalytic amounts of Pd(PPh3)(4) at 100 degrees C provides a valuable new route to 2,5-disubstituted furans 3. Most probably, the furan ring is generated through an annulation reaction promoted by sigma-arylpalladium complexes generated in situ and involving the nucleophilic attack of the ketonic oxygen across the carbon-carbon triple bond coordinated to palladium, followed by the base-catalyzed isomerization of the resultant stereoisomeric 2,5-dialkylidenetetrahydrofuran intermediates 4 and 5. The reaction is highly chemoselective. No evidence was obtained of carboannulation products. The reaction temperature has proven to be crucial for the success of the methodology. The K2CO3:alkyne ratio also affects the reaction outcome. The highest yields of furan derivatives have been obtained with aryl halides containing electron-withdrawing substituents, very likely because the higher acidity of the methylene protons of 4 and 5 favors the isomerization step. Extension of the methodology to methyl 3-oxo-7-substituted-6-heptynoates leads to the formation of 2,5-disubstituted furans containing a branched side chain. The presence of an alkyl substituent on the C-2 of the staring alkyne, however, seems to prevent the isomerization step. Treatment of ethyl 2-methyl-3-oxo-6-heptynoate under our standard conditions produced in fact the 2,5-dialkylidene derivative 5p in 42% yield, and no evidence of the corresponding furan derivative was attained.