2-benzylidene-1,3-dimesityl-2,3-dihydro-1H-imidazole | 1394238-38-0

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: 2-benzylidene-1,3-dimesityl-2,3-dihydro-1H-imidazole
• 英文别名: 2-Benzylidene-1,3-bis(2,4,6-trimethylphenyl)imidazole
• CAS: 1394238-38-0
• 化学式: C₂₈H₃₀N₂
• 分子量: 394.56
• InChiKey: VAICVGGTNJRMAP-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  7.9
• 重原子数：
  30
• 可旋转键数：
  3
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.21
• 拓扑面积：
  6.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  2-benzylidene-1,3-dimesityl-2,3-dihydro-1H-imidazole 在 (1R)-(−)-(10-camphorsulfonyl)oxaziridine 作用下， 以 氘代四氢呋喃 为溶剂， 反应 0.05h， 生成 1,3-dimesityl-1H-imidazol-2(3H)-one 、 苯甲醛
  参考文献：
  名称：

  螺环氧化物中间体参与N-杂环卡宾（NHC）催化的苯并缩合反应的研究-脱氧布雷斯洛中间体的氧化方法

  摘要：

  AbstractThe involvement of a spiroepoxide, an isomer of the Breslow intermediate, in the catalytic cycle of the N‐heterocyclic carbene (NHC)‐catalyzed benzoin condensation was suggested by S. Gronert in 2007, based on calculations. To test this hypothesis, enediamines were generated in situ from (in part 13C‐labeled) N‐heterocyclic carbenes, benzyl bromide and base, and subsequently treated with various single‐oxygen atom oxidants. Clean oxidation occurred with a triazolylidene‐derived enediamine and an N‐sulfonyloxaziridine as oxidant, but NMR monitoring gave no hint to the accumulation of a spiroepoxide. Instead, oxidative cleavage of the enediamine to the free carbene and benzaldehyde was observed, with subsequent oxidation of the carbene to a urea. Presumably, electrophilic oxygenation of the enediamine occurs at the exocyclic methylene carbon atom and affords a zwitterion – identical to the primary carbene‐aldehyde adduct of the benzoin cycle – which undergoes retro‐cleavage to carbene and aldehyde. However, the occurrence of a spiroepoxide as transient intermediate of the oxidative CC bond cleavage cannot rigorously be excluded.magnified image

  DOI：

  10.1002/adsc.201300801
• 作为产物：
  描述：

  溴甲苯 、 1,3-双(2,4,6-三甲基苯基)氯化咪唑 在 potassium tert-butylate 、 sodium hydride 作用下， 以 四氢呋喃 为溶剂， 反应 20.25h， 以90%的产率得到2-benzylidene-1,3-dimesityl-2,3-dihydro-1H-imidazole
  参考文献：
  名称：

  脱氧布雷斯洛中间体的亲核反应性：芳香度如何影响N-杂环卡宾的催化活性？

  摘要：

  芳香族还是非芳香族？动力学研究表明，结构类似的饱和和不饱和N-杂环卡宾具有几乎相同的亲核反应性，而相应的脱氧Breslow中间体则有很大不同。

  DOI：

  10.1002/anie.201202327

文献信息

• US7758897B2
  申请人：——

  公开号：US7758897B2

  公开（公告）日：2010-07-20
• Nucleophilic Reactivities of Deoxy Breslow Intermediates: How Does Aromaticity Affect the Catalytic Activities of N-Heterocyclic Carbenes?
  作者：Biplab Maji、Markus Horn、Herbert Mayr

  DOI：10.1002/anie.201202327

  日期：2012.6.18

  Aromatic or nonaromatic? Kinetic investigations show that structurally analogous saturated and unsaturated N‐heterocyclic carbenes have almost identical nucleophilic reactivities, while the corresponding deoxy Breslow intermediates differ dramatically.

  芳香族还是非芳香族？动力学研究表明，结构类似的饱和和不饱和N-杂环卡宾具有几乎相同的亲核反应性，而相应的脱氧Breslow中间体则有很大不同。
• On the Involvement of a Spiroepoxide Intermediate in N-Heterocyclic Carbene (NHC)-Catalyzed Benzoin Condensations - An Approach by Oxygenation of Deoxy-Breslow Intermediates
  作者：Albrecht Berkessel、Silvia Elfert

  DOI：10.1002/adsc.201300801

  日期：2014.2.10

  AbstractThe involvement of a spiroepoxide, an isomer of the Breslow intermediate, in the catalytic cycle of the N‐heterocyclic carbene (NHC)‐catalyzed benzoin condensation was suggested by S. Gronert in 2007, based on calculations. To test this hypothesis, enediamines were generated in situ from (in part 13C‐labeled) N‐heterocyclic carbenes, benzyl bromide and base, and subsequently treated with various single‐oxygen atom oxidants. Clean oxidation occurred with a triazolylidene‐derived enediamine and an N‐sulfonyloxaziridine as oxidant, but NMR monitoring gave no hint to the accumulation of a spiroepoxide. Instead, oxidative cleavage of the enediamine to the free carbene and benzaldehyde was observed, with subsequent oxidation of the carbene to a urea. Presumably, electrophilic oxygenation of the enediamine occurs at the exocyclic methylene carbon atom and affords a zwitterion – identical to the primary carbene‐aldehyde adduct of the benzoin cycle – which undergoes retro‐cleavage to carbene and aldehyde. However, the occurrence of a spiroepoxide as transient intermediate of the oxidative CC bond cleavage cannot rigorously be excluded.magnified image