8-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one | 573690-67-2

• 分子结构分类: 有机化合物 - 苯丙烷和聚酮 - 黄酮类化合物
• 英文名称: 8-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one
• 英文别名: 8-bromoquercetin；8-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxychromen-4-one
• CAS: 573690-67-2
• 化学式: C₁₅H₉BrO₇
• 分子量: 381.136
• InChiKey: VVDGZNCCJOUXMD-UHFFFAOYSA-N

物化性质

• 沸点：
  663.1±55.0 °C(Predicted)
• 密度：
  2.069±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.9
• 重原子数：
  23
• 可旋转键数：
  1
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  127
• 氢给体数：
  5
• 氢受体数：
  7

反应信息

• 作为反应物：
  描述：

  8-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one 在 盐酸 作用下， 以 丙酮 为溶剂， 生成 槲皮素
  参考文献：
  名称：

  Solvent-dependent release of bromine from bromoquercetins

  摘要：

  Quercetin, 6-bromoquercetin (3), and 8-bromoquercetin (4) undergo H/D exchange at 6- and 8-positions, in acetone-d(4) and methanol-d(4), catalyzed by acids and bases. The base-catalyzed process is faster, and in acetone-d(6) the half-lives of H-8 and H-6 are 56.5 and 48.6 h, respectively. A high regioselectivity at the position 8 of quercetin is observed under acid-catalysis in both solvents but in methanol-d(4) regioselectivity is retained even under base-catalysis. On the other hand, 6,8-dibromoquercetin (2), 4 and 6,8-dibromo-2'-hydroxyquercetin (5) manifest the ability of exchanging bromine with hydrogen (or deuterium) under acid-catalysis in acetone and other enolizable ketones (e.g., methyl ethyl ketone, acetylacetone, and isophorone). These bromophenols release bromine from their 8-position only, in a slow bromination process that likely involves their protonated form (arenium ion I) as brominating agent and the enol of the above ketones as Br-acceptor. The arenium ion I of these bromophenols is expected to be a powerful electrophile and its formation is most likely to be rate-determining. (C) 2014 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tetlet.2014.05.110
• 作为产物：
  描述：

  槲皮素 在 2,3-二溴-3-苯基丙酸 、 caesium carbonate 作用下， 以 N,N-二甲基甲酰胺 为溶剂， 反应 16.0h， 以25%的产率得到8-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one
  参考文献：
  名称：

  黄酮类化合物的温和选择性溴化方法

  摘要：

  开发了一种在碱存在下使用 α,β-二溴氢化肉桂酸以良好收率温和选择性溴化简单芳香族化合物和黄酮类化合物的新方法。该程序能够对氧化或自由基攻击高度敏感的化合物进行选择性单溴化或二溴化。制备了水飞蓟素黄酮木脂素和相关黄酮类化合物的新型溴化衍生物。这些溴化衍生物可在进一步合成中用作有价值的合成中间体。

  DOI：

  10.1021/acs.jnatprod.0c00655

文献信息

• Synthesis of 6- or 8-Bromo Flavonoids by Regioselective Mono-Bromination and Deprotection Protocol from Flavonoid Alkyl Ethers
  作者：Guojun Pan、Ke Yang、Yantao Ma、Xia Zhao、Kui Lu、Peng Yu

  DOI：10.1002/bkcs.10286

  日期：2015.5

  C‐6 and C‐8 monobromo flavonoids are important building blocks for the synthesis of flavonoid natural products and their derivatives. Bromination of suitably alkylated flavonoids with N‐bromosuccinimide in dichloromethane (DCM), followed by deprotection with BCl3 , gives either a C‐6 or a C‐8 monobromo flavonoid in high yield and with high regioselectivity, depending on the protection pattern of the

  C-6和C-8单溴类黄酮是合成类黄酮天然产物及其衍生物的重要组成部分。用N-溴琥珀酰亚胺在二氯甲烷（DCM）中溴化适当烷基化的类黄酮，然后用BCl 3脱保护，从而以高收率和高区域选择性获得C-6或C-8单溴类黄酮，具体取决于该化合物的保护方式C-5和C-7 OH基团。温和和中性条件对于酸不稳定底物的区域选择性溴化特别有用。
• Unveiling the chemistry behind bromination of quercetin: the ‘violet chromogen’
  作者：Mario C. Foti、Concetta Rocco

  DOI：10.1016/j.tetlet.2014.01.081

  日期：2014.2

  Bromination of quercetin with N-bromosuccinimide in neutral aqueous methanol occurs surprisingly in the electron-deficient A-ring only. Deprotonation of the acidic 7-OH is a major driver of this regioselective reaction. The increase of electron density makes in fact the quercetin anion suitable for an electrophilic attack by bromine at positions 8 and 6. Several pieces of evidence (NMR spectra and HID exchange) are presented to substantiate the mechanism advanced. Bromoquinones/quinomethides produced in excess of N-bromosuccinimide are responsible for the formation of a stable 'violet chromogen'. (C) 2014 Elsevier Ltd. All rights reserved.
• Mild and Selective Method of Bromination of Flavonoids
  作者：Martina Hurtová、David Biedermann、Marek Kuzma、Vladimír Křen

  DOI：10.1021/acs.jnatprod.0c00655

  日期：2020.11.25

  in good yields using α,β-dibromohydrocinnamic acid in the presence of a base. This procedure enables selective mono- or dibromination of compounds highly sensitive to oxidative or radical attack. New brominated derivatives of silymarin flavonolignans and related flavonoids were prepared. These brominated derivatives can be used as valuable synthetic intermediates in further synthesis.

  开发了一种在碱存在下使用 α,β-二溴氢化肉桂酸以良好收率温和选择性溴化简单芳香族化合物和黄酮类化合物的新方法。该程序能够对氧化或自由基攻击高度敏感的化合物进行选择性单溴化或二溴化。制备了水飞蓟素黄酮木脂素和相关黄酮类化合物的新型溴化衍生物。这些溴化衍生物可在进一步合成中用作有价值的合成中间体。
• Solvent-dependent release of bromine from bromoquercetins
  作者：Mario C. Foti、Concetta Rocco

  DOI：10.1016/j.tetlet.2014.05.110

  日期：2014.7

  Quercetin, 6-bromoquercetin (3), and 8-bromoquercetin (4) undergo H/D exchange at 6- and 8-positions, in acetone-d(4) and methanol-d(4), catalyzed by acids and bases. The base-catalyzed process is faster, and in acetone-d(6) the half-lives of H-8 and H-6 are 56.5 and 48.6 h, respectively. A high regioselectivity at the position 8 of quercetin is observed under acid-catalysis in both solvents but in methanol-d(4) regioselectivity is retained even under base-catalysis. On the other hand, 6,8-dibromoquercetin (2), 4 and 6,8-dibromo-2'-hydroxyquercetin (5) manifest the ability of exchanging bromine with hydrogen (or deuterium) under acid-catalysis in acetone and other enolizable ketones (e.g., methyl ethyl ketone, acetylacetone, and isophorone). These bromophenols release bromine from their 8-position only, in a slow bromination process that likely involves their protonated form (arenium ion I) as brominating agent and the enol of the above ketones as Br-acceptor. The arenium ion I of these bromophenols is expected to be a powerful electrophile and its formation is most likely to be rate-determining. (C) 2014 Elsevier Ltd. All rights reserved.