2-methyl-3-(1-methyl-2-butylcyclopropenyl)inden-1-one | 137234-04-9

• 分子结构分类: 有机化合物 - 苯类化合物 - 萘
• 英文名称: 2-methyl-3-(1-methyl-2-butylcyclopropenyl)inden-1-one
• 英文别名: 3-(2-Butyl-1-methylcycloprop-2-en-1-yl)-2-methylinden-1-one
• CAS: 137234-04-9
• 化学式: C₁₈H₂₀O
• 分子量: 252.356
• InChiKey: QRTFJGIFHKVIIY-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.5
• 重原子数：
  19
• 可旋转键数：
  4
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.39
• 拓扑面积：
  17.1
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  2-methyl-3-(1-methyl-2-butylcyclopropenyl)inden-1-one 在 dirhodium tetraacetate 作用下， 以92%的产率得到3,8a-dimethyl-8,8a-dihydro-8-oxocyclopentindene
  参考文献：
  名称：

  Rhodium-catalyzed ring-opening reaction of cyclopropenes. Control of regioselectivity by the oxidation state of the metal

  摘要：

  The Rh(II)-catalyzed reaction of unsymmetrically substituted cyclopropenes gives substituted furans derived from cleavage of the less substituted sigma-bond. In contrast, Rh(I) catalysis results in cleavage of the more substituted sigma-bond producing a regioisomeric set of furans.

  DOI：

  10.1021/jo00025a005
• 作为产物：
  描述：

  2-Diazo-1-(2-prop-1-ynylphenyl)propan-1-one 、 1-己炔 在 dirhodium tetraacetate 作用下， 生成 2-methyl-3-(1-methyl-2-butylcyclopropenyl)inden-1-one
  参考文献：
  名称：

  Rhodium-catalyzed ring-opening reaction of cyclopropenes. Control of regioselectivity by the oxidation state of the metal

  摘要：

  The Rh(II)-catalyzed reaction of unsymmetrically substituted cyclopropenes gives substituted furans derived from cleavage of the less substituted sigma-bond. In contrast, Rh(I) catalysis results in cleavage of the more substituted sigma-bond producing a regioisomeric set of furans.

  DOI：

  10.1021/jo00025a005

文献信息

• Cyclization Reactions of Rhodium Carbene Complexes. Effect of Composition and Oxidation State of the Metal
  作者：Albert Padwa、Jamal M. Kassir、Simon L. Xu

  DOI：10.1021/jo962271r

  日期：1997.3.1

  Treatment of o-(1,7-octadiynyl)benzoyldiazoethane with rhodium(II) octanoate in pentane resulted in a double internal/internal alkyne insertion reaction producing a labile bicyclo[4.1.0]hept-1(7)ene derivative which readily undergoes a Diels-Alder reaction with diphenylisobenzofuran. Changing the solvent from pentane to CH2Cl2 afforded a 2:1 mixture of cis- and trans-alkenyl-substituted indenones. Stepwise cyclization involving a set of dipolar intermediates occurs in CH2Cl2 whereas metallocyclobutenes are involved when pentane is used as the solvent. The rhodium(II) carboxylate catalyzed reaction of unsymmetrically substituted cyclopropenes gives substituted furans derived from cleavage of the less substituted beta-bond. Thus, treatment of 3-benzoyl-3-methyl-1-(n-butyl)cyclopropene with Rh2OAc4 afforded a 26:1 mixture of 2-phenyl-3-methyl-4-(n-butyl)- and 2-phenyl-3-methyl-5-(n-butyl)furan. In contrast, the [ClRh(CO)(2)](2)-catalyzed reaction resulted in cleavage of the more substituted sigma-bond producing only 2-phenyl-3-methyl-5-(n-butyl)furan. Both reactions involve electrophilic attack of the rhodium metal on the less substituted carbon atom of the cyclopropene pi-bond to give the most stabilized cyclopropyl carbocation. Ring opening followed by rapid electrocyclization to the furan occurs with the Rh(IH) catalyst. With the Rh(I) catalyst, the ring-opened species preferentially cyclizes to a metallocyclobutene intermediate which then equilibrates with the thermodynamically more stable isomer prior to furan formation. The Rh(I)-catalyzed reaction of 3-benzoyl-1-propylcyclopropene with various terminal alkynes gives 4-alkyl-4-propyl-7-phenyloxepins in good yield. These reactions involve electrophilic attack of the rhodium metal on the more substituted carbon of the cyclopropene; pi-bond to give a rhodium carbene complex, This metallo carbenoid undergoes a subsequent [2 + 2] cycloaddition with terminal acetylenes, The resulting rhodacycle rearranges by a formal 1,5-sigmatropic shift, and this is followed by reductive elimination of rhodium to produce the observed oxepin.