1,2-dibromo-3,3-dimethylcyclopropene | 170744-77-1

• 分子结构分类: 有机化合物 - 有机卤素化合物 - 乙烯基卤化物
• 英文名称: 1,2-dibromo-3,3-dimethylcyclopropene
• CAS: 170744-77-1
• 化学式: C₅H₆Br₂
• 分子量: 225.911
• InChiKey: YVFSJHSDTPDZQS-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.8
• 重原子数：
  7
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.6
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  0

反应信息

• 作为反应物：
  描述：

  丁烯酮 、 1,2-dibromo-3,3-dimethylcyclopropene 以 乙醚 为溶剂， 反应 3.0h， 生成 1-acetyl-2-bromo-2-(1-bromo-2-methylprop-1-enyl)cyclopropane
  参考文献：
  名称：

  The generation and trapping of 1,2-Dibromo-3-methylbut-2-en-1-ylidenes

  摘要：

  1,2-Dibromo-3,3-dimerhylcyclopropene, generated by debromination of 1,1,2,2-tetrabromo-3,3-dimethylcyclopropane on reaction with methyllithium, ring-opens at 0-20 degrees C to produce 1,2-dibromo-3-methylbut-2-en-1-ylidene. This is trapped by alkenes to give vinylcyclopropanes. In the case of electron rich alkenes, the stereochemistry is retained in the product, suggesting that a singlet carbene is involved. In the case of alpha,beta-unsaturated esters, ketones or nitriles, the major cyclopropane produced has the vinyl and electron-withdrawing groups cis-related. 3-(2-Methoxy-ethyl)-3-methyl- and 3-(2-bromoethyl)-3-methyl-1,2-dibromocyclopropenes also ring-open at ambient temperature but little stereoselectivity is observed in the trapping of the derived vinyl-carbenes by alkenes. The reaction of 3-(2-hrdroxrethyl)-3-methyl-1,1,2,2-tetrabromocyclopropane with methyl lithium or diethylphosphite and triethylamine does not lead to an isolable cyclo-propene, but instead to Z-1,2-dibromo-3-methylbuta-1,3-diene; quenching with deuterium oxide at low temperature leads to the incorporation of deuterium at C-1.

  DOI：

  10.1016/0040-4020(95)00448-h
• 作为产物：
  描述：

  1,1,2,2-tetrabromo-3,3-dimethylcyclopropane 在 甲基锂 作用下， 以 乙醚 为溶剂， 生成 1,2-dibromo-3,3-dimethylcyclopropene
  参考文献：
  名称：

  The generation and trapping of 1,2-Dibromo-3-methylbut-2-en-1-ylidenes

  摘要：

  1,2-Dibromo-3,3-dimerhylcyclopropene, generated by debromination of 1,1,2,2-tetrabromo-3,3-dimethylcyclopropane on reaction with methyllithium, ring-opens at 0-20 degrees C to produce 1,2-dibromo-3-methylbut-2-en-1-ylidene. This is trapped by alkenes to give vinylcyclopropanes. In the case of electron rich alkenes, the stereochemistry is retained in the product, suggesting that a singlet carbene is involved. In the case of alpha,beta-unsaturated esters, ketones or nitriles, the major cyclopropane produced has the vinyl and electron-withdrawing groups cis-related. 3-(2-Methoxy-ethyl)-3-methyl- and 3-(2-bromoethyl)-3-methyl-1,2-dibromocyclopropenes also ring-open at ambient temperature but little stereoselectivity is observed in the trapping of the derived vinyl-carbenes by alkenes. The reaction of 3-(2-hrdroxrethyl)-3-methyl-1,1,2,2-tetrabromocyclopropane with methyl lithium or diethylphosphite and triethylamine does not lead to an isolable cyclo-propene, but instead to Z-1,2-dibromo-3-methylbuta-1,3-diene; quenching with deuterium oxide at low temperature leads to the incorporation of deuterium at C-1.

  DOI：

  10.1016/0040-4020(95)00448-h

文献信息

• The generation and trapping of 1,2-Dibromo-3-methylbut-2-en-1-ylidenes
  作者：Ahmad R. Al Dulayymi、Juma'a R. Al Dulayymi、Mark S. Baird、Leela Rajaram

  DOI：10.1016/0040-4020(95)00448-h

  日期：1995.7

  1,2-Dibromo-3,3-dimerhylcyclopropene, generated by debromination of 1,1,2,2-tetrabromo-3,3-dimethylcyclopropane on reaction with methyllithium, ring-opens at 0-20 degrees C to produce 1,2-dibromo-3-methylbut-2-en-1-ylidene. This is trapped by alkenes to give vinylcyclopropanes. In the case of electron rich alkenes, the stereochemistry is retained in the product, suggesting that a singlet carbene is involved. In the case of alpha,beta-unsaturated esters, ketones or nitriles, the major cyclopropane produced has the vinyl and electron-withdrawing groups cis-related. 3-(2-Methoxy-ethyl)-3-methyl- and 3-(2-bromoethyl)-3-methyl-1,2-dibromocyclopropenes also ring-open at ambient temperature but little stereoselectivity is observed in the trapping of the derived vinyl-carbenes by alkenes. The reaction of 3-(2-hrdroxrethyl)-3-methyl-1,1,2,2-tetrabromocyclopropane with methyl lithium or diethylphosphite and triethylamine does not lead to an isolable cyclo-propene, but instead to Z-1,2-dibromo-3-methylbuta-1,3-diene; quenching with deuterium oxide at low temperature leads to the incorporation of deuterium at C-1.