6-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one

• 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: 6-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one
• 英文别名: 6‑bromoquercetin；6-bromoquercetin；6-Monobromoquercetin；6-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxychromen-4-one
• 化学式: C₁₅H₉BrO₇
• 分子量: 381.136
• InChiKey: OMJJHHBJCTVTFL-UHFFFAOYSA-N

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

• 作为产物：
  描述：

  槲皮素 在 溴 作用下， 以 1,4-二氧六环 为溶剂， 生成 6-bromo-2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one
  参考文献：
  名称：

  分光光度法和DFT研究6-溴槲皮素在水溶液中的行为

  摘要：

  在不同条件下的水介质中研究了酸碱活性，酮-烯醇互变异构现象和6-溴槲皮素的络合特性。在各种离子强度下，已在pH范围内确定了解离常数（p K a）。质子化过程的分析是在HCl的强酸性溶液中进行的。用三价镧系元素研究了络合物。获得了单络合物物种ML（M（III）= Ce，Pr，Nd，Sm，Eu，Gd，Tb，Dy，Er，Tm，Yb，Lu）的形成常数。进行DFT计算以解释和验证收到的结果。

  DOI：

  10.1007/s11696-019-00725-w

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。
• 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.
• Synthesis of biologically active bromine derivatives of quercetin
  作者：A. D. Nagimova、G. E. Zhusupova、M. S. Erzhanova

  DOI：10.1007/bf01375117

  日期：1996.9
• 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.