3,5-bis(4-bromophenyl)-4,4-dimethyl-4H-pyrazole | 155886-83-2

• 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: 3,5-bis(4-bromophenyl)-4,4-dimethyl-4H-pyrazole
• 英文别名: 3,5-Bis(4-bromophenyl)-4,4-dimethylpyrazole
• CAS: 155886-83-2
• 化学式: C₁₇H₁₄Br₂N₂
• 分子量: 406.12
• InChiKey: ZKUFAVODLQZZBZ-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5.7
• 重原子数：
  21
• 可旋转键数：
  2
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.18
• 拓扑面积：
  24.7
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  3,5-bis(4-bromophenyl)-4,4-dimethyl-4H-pyrazole 在 三氟乙酸 作用下， 以 二氯甲烷 、 氘代苯 为溶剂， 反应 0.17h， 生成 3,3-Dimethyl-2,4-bis(4'-bromophenyl)-endo-tricyclo<3.3.0.0^2,4>oct-6-ene
  参考文献：
  名称：

  Electronic Substituent Effects on the Acid-Catalyzed [4+ + 2] Cycloaddition of Isopyrazoles with Cyclopentadiene and the Photochemical and Thermal Denitrogenation of the Resulting 1,4-Diaryl-7,7-dimethyl-2,3-diazabicyclo[2.2.1]hept-2-ene Azoalkanes to Bicyclo[2.1.0]pentanes

  摘要：

  Eight symmetrically disubstituted 3,5-diaryl-4,4-dimethylisopyrazoles 6 with para and meta substituents (OMe, Me, H, F, Cl, Br, CN, NO2) and two unsymmetrically para-substituted derivatives (OMe and NO2; Me and CO(2)Me) were synthesized from the corresponding 1,3-diaryl-2,2-dimethyl-1,3-propanediones 5, which in turn were readily available by 2,2-dimethylation of the diones 4. The acid-catalyzed cycloaddition of cyclopentadiene to the isopyrazoles 6, a Diels-Alder reaction with inverse electron demand, afforded the 1,4-diaryl-substituted gem-dimethyl azoalkanes 7 of the diazabicyco[2.2.1]hept-2-ene (DBH) type. The cycloadduct yields were strongly dependent on the nature of the aryl substituents and highest for the electron-withdrawing substituents. In acidic solution, the azoalkanes showed cycloreversion to generate an equilibrium between isopyrazole 6, cyclopentadiene, and azoalkane 7. For the p-methoxy derivative, cycloreversion was essentially quantitative, whereas only 20% cycloreversion occurred for the para nitro compound. A positive Hammett rho value (rho = 3.24 for 2 equiv of CF3COOH) was determined for the equilibrium constants of the acid-catalyzed [4(+) + 2] cycloaddition. The unsymmetrically substituted isopyrazoles gave two regioisomeric cycloadducts with a slight excess of one isomer. The direct and triplet-sensitized photochemical and thermal denitrogenation of the azoalkanes 7 gave in quantitative yields the 1,4-diaryl-substituted bicyclo[2.1.0]pentanes (BCP) 8 with retention of configuration. The azoalkanes 7 and the housanes 8 are more persistent than the related 1,4-diaryl-substituted DBH and BCP derivatives. The stabilizing effect is rationalized in terms of less favorable benzylic conjugation in the transition states for C-N (azoalkanes) and C-C (housanes) bond cleavage due to steric interactions between the geminal methyl groups at the methane bridge and the diaryl substituents at the bridgehead sites.

  DOI：

  10.1021/jo00093a010
• 作为产物：
  描述：

  (1α,4α,4aα,7aα)-4,4a,7,7a-Tetrahydro-8,8-dimethyl-1,4-bis(4'-bromophenyl)-1,4-methano-1H-cyclopentapyridazine 在 三氟乙酸 作用下， 以 氘代氯仿 为溶剂， 生成 3,5-bis(4-bromophenyl)-4,4-dimethyl-4H-pyrazole
  参考文献：
  名称：

  Electronic Substituent Effects on the Acid-Catalyzed [4+ + 2] Cycloaddition of Isopyrazoles with Cyclopentadiene and the Photochemical and Thermal Denitrogenation of the Resulting 1,4-Diaryl-7,7-dimethyl-2,3-diazabicyclo[2.2.1]hept-2-ene Azoalkanes to Bicyclo[2.1.0]pentanes

  摘要：

  Eight symmetrically disubstituted 3,5-diaryl-4,4-dimethylisopyrazoles 6 with para and meta substituents (OMe, Me, H, F, Cl, Br, CN, NO2) and two unsymmetrically para-substituted derivatives (OMe and NO2; Me and CO(2)Me) were synthesized from the corresponding 1,3-diaryl-2,2-dimethyl-1,3-propanediones 5, which in turn were readily available by 2,2-dimethylation of the diones 4. The acid-catalyzed cycloaddition of cyclopentadiene to the isopyrazoles 6, a Diels-Alder reaction with inverse electron demand, afforded the 1,4-diaryl-substituted gem-dimethyl azoalkanes 7 of the diazabicyco[2.2.1]hept-2-ene (DBH) type. The cycloadduct yields were strongly dependent on the nature of the aryl substituents and highest for the electron-withdrawing substituents. In acidic solution, the azoalkanes showed cycloreversion to generate an equilibrium between isopyrazole 6, cyclopentadiene, and azoalkane 7. For the p-methoxy derivative, cycloreversion was essentially quantitative, whereas only 20% cycloreversion occurred for the para nitro compound. A positive Hammett rho value (rho = 3.24 for 2 equiv of CF3COOH) was determined for the equilibrium constants of the acid-catalyzed [4(+) + 2] cycloaddition. The unsymmetrically substituted isopyrazoles gave two regioisomeric cycloadducts with a slight excess of one isomer. The direct and triplet-sensitized photochemical and thermal denitrogenation of the azoalkanes 7 gave in quantitative yields the 1,4-diaryl-substituted bicyclo[2.1.0]pentanes (BCP) 8 with retention of configuration. The azoalkanes 7 and the housanes 8 are more persistent than the related 1,4-diaryl-substituted DBH and BCP derivatives. The stabilizing effect is rationalized in terms of less favorable benzylic conjugation in the transition states for C-N (azoalkanes) and C-C (housanes) bond cleavage due to steric interactions between the geminal methyl groups at the methane bridge and the diaryl substituents at the bridgehead sites.

  DOI：

  10.1021/jo00093a010

文献信息

• 1,3-Diradicals Embedded in Curved Paraphenylene Units: Singlet versus Triplet State and In-Plane Aromaticity
  作者：Yuki Miyazawa、Zhe Wang、Misaki Matsumoto、Sayaka Hatano、Ivana Antol、Eiichi Kayahara、Shigeru Yamago、Manabu Abe

  DOI：10.1021/jacs.1c01329

  日期：2021.5.19

  interactions and singlet versus triplet state, as well as their unique characteristics such as in-plane aromaticity. A triplet ground state was predicted for the larger 1,3-diradicals, such as the seven- and eight-paraphenylene-unit-containing diradicals DR-7CPP (n = 4) and DR-8CPP (n = 5), by quantum chemical calculations. The smaller-sized diradicals DR-(n+3)CPPs (n = 0–3) were found to possess singlet ground

  从基础化学以及材料科学的角度来看，弯曲的π共轭分子和开壳结构引起了人们的极大关注。在这项研究中，研究了嵌入弯曲的环对亚苯基（CPP s）结构DR-（n +3）CPP s（n = 0-5）中的1,3-二基（DR s）的化学性质，以了解自旋-自旋相互作用，单重态与三重态的曲率和系统大小，以及它们的独特特征，例如平面内的芳香性。预测较大的1,3-双基自由基为三重态基态，例如含七和八对亚苯基单元的双基自由基DR - 7CPP（n = 4）和DR - 8CPP（n = 5），通过量子化学计算。发现较小的双基自由基DR-（n +3）CPP s（n = 0-3）具有单重态基态。因此，基态自旋多重性由对亚苯基环的大小控制。DR - 6CPP在其含偶氮的前驱体（AZ - 6CPP）的光化学脱氮中的实验生成证实了其对基态自旋多重性的尺寸效应。）。有趣的是，在较小尺寸的单重态（例如S- DR - 4CPP（n =
• 一种以含氮五元杂环为核心的化合物及其在有机电致发光器件上的应用
  申请人：中节能万润股份有限公司

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• 一种以含氮五元杂环为核心的有机电致发光化合物及其应用
  申请人：江苏三月光电科技有限公司

  公开号：CN106467518A

  公开（公告）日：2017-03-01

  本发明公开了一种以含氮五元杂环为核心的有机电致发光化合物及其应用，该化合物以含氮五元杂环为核心，具有分子间不易结晶、不易聚集、具有良好成膜性的特点。将本发明化合物作为发光层材料应用于有机电致发光器件上，应用本发明化合物的有机电致发光器件具有良好的光电性能表现，可以更好的适应和满足面板制造企业的应用要求。