(Z)-5-(iodomethylene)-3-methyl-4-(prop-1-en-2-yl)-5,6-dihydropyran-2-one | 952718-71-7

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡喃
• 英文名称: (Z)-5-(iodomethylene)-3-methyl-4-(prop-1-en-2-yl)-5,6-dihydropyran-2-one
• 英文别名: (5Z)-5-(iodomethylidene)-3-methyl-4-prop-1-en-2-ylpyran-2-one
• CAS: 952718-71-7
• 化学式: C₁₀H₁₁IO₂
• 分子量: 290.101
• InChiKey: RQTDKWLEXVOLEC-XBXARRHUSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.5
• 重原子数：
  13
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.3
• 拓扑面积：
  26.3
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  (Z)-5-(iodomethylene)-3-methyl-4-(prop-1-en-2-yl)-5,6-dihydropyran-2-one 、 3-甲氧基苯硼酸 在 四(三苯基膦)钯 potassium phosphate 作用下， 以 甲苯 为溶剂， 反应 0.17h， 以83%的产率得到(Z)-5-(m-methoxybenzylidene)-3-methyl-4-(prop-1-en-2-yl)-5,6-dihydropyran-2-one
  参考文献：
  名称：

  trans-RhCl(CO)(PPh₃)₂-Catalyzed Monomeric and Dimeric Cycloisomerization of Propargylic 2,3-Dienoates. Establishment of α,β-Unsaturated δ-Lactone Rings by Cyclometallation

  摘要：

  Cyclometallation of two unsaturated carbon-carbon bonds usually requires the application of low-valent metal catalysts, which could cleave the propargylic ester linkage. Thus, it is desirable to identify a catalyst which could undergo cyclometallation without cleaving the propargylic ester linkage. In this paper, we used trans-RhCI(CO)(PPh3)(2) to realize the cyclometallation of propargylic 2,3-dienoates. The substituents at the 4-position of allenoate moiety nicely control the reaction pathway: when the 4-position of propargylic 2,3-dienoate 1 was monosubstituted with an aryl group, the bicyclic intermediate 7 formed by the cyclometallation could highly selectively undergo carbometalation with the alkyne moiety in the second molecule of propargylic 2,3-dienoate 1 to afford metallabicyclic intermediates 8a or 8b. Subsequent reductive elimination would afford 9, which could undergo an intramolecular Diels-Alder reaction resulting in the formation of polycyclic bis(delta-lactone)-containing structures 2. The intermediate could be trapped by adding 3-methoxyprop-1-yne affording cyclization-aromatization product 4p highly selectively. If the substituent at the 4-positon of the 2,3-allenoate moiety has a beta-H atom, sequential unimolecular cyclometallation/beta-H elimination/reductive elimination occurs to afford cross-conjugated 5(Z)-alkylidene-4-alkenyl-5,6-dihydropyran-2-ones. The Z-stereochemistry of the exo double bond was determined by the cyclometallation. Some of the a,p-unsaturated delta-lactones could be easily converted to other synthetically useful compounds via reduction reaction, hydrogenation, and iodination/coupling protocol.

  DOI：

  10.1021/ja073582u
• 作为产物：
  描述：

  (Z)-3-methyl-4-(prop-1-en-2-yl)-5-((trimethylsilyl)methylene)-5,6-dihydropyran-2-one 在 N-碘代丁二酰亚胺 作用下， 以 乙腈 为溶剂， 反应 10.0h， 以88%的产率得到(Z)-5-(iodomethylene)-3-methyl-4-(prop-1-en-2-yl)-5,6-dihydropyran-2-one
  参考文献：
  名称：

  trans-RhCl(CO)(PPh₃)₂-Catalyzed Monomeric and Dimeric Cycloisomerization of Propargylic 2,3-Dienoates. Establishment of α,β-Unsaturated δ-Lactone Rings by Cyclometallation

  摘要：

  Cyclometallation of two unsaturated carbon-carbon bonds usually requires the application of low-valent metal catalysts, which could cleave the propargylic ester linkage. Thus, it is desirable to identify a catalyst which could undergo cyclometallation without cleaving the propargylic ester linkage. In this paper, we used trans-RhCI(CO)(PPh3)(2) to realize the cyclometallation of propargylic 2,3-dienoates. The substituents at the 4-position of allenoate moiety nicely control the reaction pathway: when the 4-position of propargylic 2,3-dienoate 1 was monosubstituted with an aryl group, the bicyclic intermediate 7 formed by the cyclometallation could highly selectively undergo carbometalation with the alkyne moiety in the second molecule of propargylic 2,3-dienoate 1 to afford metallabicyclic intermediates 8a or 8b. Subsequent reductive elimination would afford 9, which could undergo an intramolecular Diels-Alder reaction resulting in the formation of polycyclic bis(delta-lactone)-containing structures 2. The intermediate could be trapped by adding 3-methoxyprop-1-yne affording cyclization-aromatization product 4p highly selectively. If the substituent at the 4-positon of the 2,3-allenoate moiety has a beta-H atom, sequential unimolecular cyclometallation/beta-H elimination/reductive elimination occurs to afford cross-conjugated 5(Z)-alkylidene-4-alkenyl-5,6-dihydropyran-2-ones. The Z-stereochemistry of the exo double bond was determined by the cyclometallation. Some of the a,p-unsaturated delta-lactones could be easily converted to other synthetically useful compounds via reduction reaction, hydrogenation, and iodination/coupling protocol.

  DOI：

  10.1021/ja073582u