2,3-Dibromo-5-trifluoromethyl-[1,4]benzoquinone | 197858-57-4

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 2,3-Dibromo-5-trifluoromethyl-[1,4]benzoquinone
• 英文别名: 2,3-Dibromo-5-(trifluoromethyl)cyclohexa-2,5-diene-1,4-dione
• CAS: 197858-57-4
• 化学式: C₇HBr₂F₃O₂
• 分子量: 333.887
• InChiKey: KWXCCEMBDNXYMB-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.7
• 重原子数：
  14
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.14
• 拓扑面积：
  34.1
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  2,3-Dibromo-5-trifluoromethyl-[1,4]benzoquinone 在 palladium on activated charcoal ammonium persulfate 、 氢气 、 silver nitrate 作用下， 以 二氯甲烷 、 水 、 甲苯 为溶剂， 生成 4-(3,4-Dibromo-2,5-dihydroxy-6-trifluoromethyl-phenyl)-cyclohexanecarboxylic acid methyl ester
  参考文献：
  名称：

  Cyclohexylene-Bridged Porphyrin Quinones with Variable Acceptor Strength as Biomimetic Models for Photosynthesis:  Evidence for Twist-Boat Conformation

  摘要：

  Rigidly and covalently linked porphyrin quinones are well-suited as biomimetic model compounds for studying the photoinduced electron transfer (PET reaction occurring in primary processes of photosynthesis. In this context, the synthesis of new porphyrin quinones with a cis-or trans-1,4-disubstituted cyclohexylene bridge linking the electron donor and the electron acceptor is reported. To study the dependence of the PET rate of the difference of the free enthalpy of the PET reaction, four quinones with different structures and therefore redox potentials were used as electron acceptor components. As a whole. two series of each four new cis-and trans-1,4-cyclohexylene-bridged porphyrin quinones with variable acceptor strength were synthesized. The most important synthetic steps comprised the free radical addition of the ester functionalized cyclohexylene bridge to the quinone, reduction of the ester to the alcohol group with lithium borohydride or DIBALH, oxidation of the alcohol to the corresponding aldehyde with PCC or TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl)/NaOCl, and condensation of these aldehydes with pyrrole and 4-methylbenzaldehyde under equilibrium conditions. Analysis of the H-1 NMR spectra unambiguously indicated the chair conformation for the cyclohexane ring of all porphyrin precursors and trans-cyclohexane-bridged porphyrin quinones, whereas the cis-cyclohexane-bridged porphyrin quinones had the cyclohexane ring in the unusual twist-boat conformation. This was additionally confirmed by an X-ray crystal structure of one of the cis-porphyrin quinones and the corresponding trans-porphyrin quinone. NOE experiments gave information about the spatial arrangement of the diastereomeric target compounds in solution.

  DOI：

  10.1021/jo970752k
• 作为产物：
  描述：

  4-氨基-3-三氟甲基苯酚 在 manganese(IV) oxide 、 硫酸 、 溴 、 2,3-二氯-5,6-二氰基-1,4-苯醌 作用下， 以 乙醚 、 二氯甲烷 、 硫酸 、 甲苯 为溶剂， 反应 8.5h， 生成 2,3-Dibromo-5-trifluoromethyl-[1,4]benzoquinone
  参考文献：
  名称：

  Cyclohexylene-Bridged Porphyrin Quinones with Variable Acceptor Strength as Biomimetic Models for Photosynthesis:  Evidence for Twist-Boat Conformation

  摘要：

  Rigidly and covalently linked porphyrin quinones are well-suited as biomimetic model compounds for studying the photoinduced electron transfer (PET reaction occurring in primary processes of photosynthesis. In this context, the synthesis of new porphyrin quinones with a cis-or trans-1,4-disubstituted cyclohexylene bridge linking the electron donor and the electron acceptor is reported. To study the dependence of the PET rate of the difference of the free enthalpy of the PET reaction, four quinones with different structures and therefore redox potentials were used as electron acceptor components. As a whole. two series of each four new cis-and trans-1,4-cyclohexylene-bridged porphyrin quinones with variable acceptor strength were synthesized. The most important synthetic steps comprised the free radical addition of the ester functionalized cyclohexylene bridge to the quinone, reduction of the ester to the alcohol group with lithium borohydride or DIBALH, oxidation of the alcohol to the corresponding aldehyde with PCC or TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl)/NaOCl, and condensation of these aldehydes with pyrrole and 4-methylbenzaldehyde under equilibrium conditions. Analysis of the H-1 NMR spectra unambiguously indicated the chair conformation for the cyclohexane ring of all porphyrin precursors and trans-cyclohexane-bridged porphyrin quinones, whereas the cis-cyclohexane-bridged porphyrin quinones had the cyclohexane ring in the unusual twist-boat conformation. This was additionally confirmed by an X-ray crystal structure of one of the cis-porphyrin quinones and the corresponding trans-porphyrin quinone. NOE experiments gave information about the spatial arrangement of the diastereomeric target compounds in solution.

  DOI：

  10.1021/jo970752k

文献信息

• Cyclohexylene-Bridged Porphyrin Quinones with Variable Acceptor Strength as Biomimetic Models for Photosynthesis:  Evidence for Twist-Boat Conformation
  作者：Henrik Dieks、Mathias O. Senge、Burkhard Kirste、Harry Kurreck

  DOI：10.1021/jo970752k

  日期：1997.12.1

  Rigidly and covalently linked porphyrin quinones are well-suited as biomimetic model compounds for studying the photoinduced electron transfer (PET reaction occurring in primary processes of photosynthesis. In this context, the synthesis of new porphyrin quinones with a cis-or trans-1,4-disubstituted cyclohexylene bridge linking the electron donor and the electron acceptor is reported. To study the dependence of the PET rate of the difference of the free enthalpy of the PET reaction, four quinones with different structures and therefore redox potentials were used as electron acceptor components. As a whole. two series of each four new cis-and trans-1,4-cyclohexylene-bridged porphyrin quinones with variable acceptor strength were synthesized. The most important synthetic steps comprised the free radical addition of the ester functionalized cyclohexylene bridge to the quinone, reduction of the ester to the alcohol group with lithium borohydride or DIBALH, oxidation of the alcohol to the corresponding aldehyde with PCC or TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl)/NaOCl, and condensation of these aldehydes with pyrrole and 4-methylbenzaldehyde under equilibrium conditions. Analysis of the H-1 NMR spectra unambiguously indicated the chair conformation for the cyclohexane ring of all porphyrin precursors and trans-cyclohexane-bridged porphyrin quinones, whereas the cis-cyclohexane-bridged porphyrin quinones had the cyclohexane ring in the unusual twist-boat conformation. This was additionally confirmed by an X-ray crystal structure of one of the cis-porphyrin quinones and the corresponding trans-porphyrin quinone. NOE experiments gave information about the spatial arrangement of the diastereomeric target compounds in solution.