7,8-Difluoroalloxazine

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 蝶啶及其衍生物
• 英文名称: 7,8-Difluoroalloxazine
• 英文别名: 7,8-difluorobenzo[g]pteridine-2,4(1H,3H)-dione；7,8-difluoro-1H-benzo[g]pteridine-2,4-dione
• 化学式: C₁₀H₄F₂N₄O₂
• 分子量: 250.164
• InChiKey: NOMTYTVEBURENV-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  0.6
• 重原子数：
  18
• 可旋转键数：
  0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  84
• 氢给体数：
  2
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  7,8-Difluoroalloxazine 、 碘甲烷 在 potassium carbonate 作用下， 以 N,N-二甲基甲酰胺 为溶剂， 以98.5%的产率得到7,8-Difluoro-1,3-dimethylalloxazine
  参考文献：
  名称：

  Mild and Efficient Flavin-Catalyzed H2O2 Oxidations

  摘要：

  Based on a previously discovered method for amine oxidations using flavins as catalysts and hydrogen peroxide as oxidant, a comparative kinetic study using NMR spectroscopy was undertaken with a series of flavins for amine and thioether oxidations. Included in this series is the newly prepared 7,8-difluoro-1,3dimethyl-5-ethyl-5,10-dihydroalIoxazine. This study shows that flavins, which bear electron-donating groups on the aromatic ring and/or the N-10 position, are less active and are deactivated during the course of the reaction, Moreover, flavins that are alkylated at the N-1 position instead of the N-10 position and having either no substituents or electron-withdrawing groups on the aromatic ring, remain the most active and stable.

  DOI：

  10.1002/1521-3765(20010105)7:1<297::aid-chem297>3.0.co;2-6
• 作为产物：
  描述：

  四氧嘧啶 、 4,5-二氟苯-1,2-二胺 在 硼酸 作用下， 以 溶剂黄146 为溶剂， 反应 2.0h， 以99%的产率得到7,8-Difluoroalloxazine
  参考文献：
  名称：

  Organocatalytic Dakin Oxidation by Nucleophilic Flavin Catalysts

  摘要：

  Flavin catalysts perform the first organocatalytic Dakin oxidation of electron-rich arylaldehydes to phenols under mild, basic conditions. Catechols are readily prepared, and the oxidation of 2-hydroxyacetophenone was achieved. Aerobic oxidation is displayed in the presence of Zn(0) as a reducing agent. This reactivity broadens the scope of biomimetic flavin catalysis in the realm of nucleophilic oxidations, providing a framework for mechanistic investigations for related oxidations, such as the Baeyer-Villiger oxidation and Weitz-Scheffer epoxidation.

  DOI：

  10.1021/ol3010326

文献信息

• Electron-Deficient Alloxazinium Salts: Efficient Organocatalysts of Mild and Chemoselective Sulfoxidations with Hydrogen Peroxide
  作者：Petra Ménová、Hana Dvořáková、Václav Eigner、Jiří Ludvík、Radek Cibulka

  DOI：10.1002/adsc.201300617

  日期：2013.11.25

  AbstractA series of substituted alloxazinium perchlorates has been prepared and tested as catalysts for the oxidation of sulfides to sulfoxides with hydrogen peroxide. The logarithms of the observed rate constants of thioanisole oxidation correlate with the Hammett σ constants of the substituents on the alloxazinium catalysts, as well as with their reduction potentials E0′ and their pKR+ values, representing the alloxazinium salt/pseudobase equilibrium. The stronger the electron‐withdrawing substituent, the more efficient is the alloxazinium catalyst. The alloxazinium salts with a cyano or trifluoromethyl group in position 8 proved to be the most efficient, operating at room temperature at small loadings, down to 0.1 mol%, achieving turnover number values of up to 640 and acceleration by a factor of 350 relative to the non‐catalyzed oxidation. The 8‐cyanoalloxazinium perchlorate was evaluated as the best catalyst; however, due to its relatively good accessibility, the 8‐(trifluoromethyl)alloxazinium perchlorate seems to be the catalyst of choice for sulfoxidations with hydrogen peroxide. It was successfully tested for the sulfoxidation of a series of aliphatic and aromatic sulfides on a preparative scale. It produced the corresponding sulfoxides in quantitative conversions and with high isolated yields (87–98%). No over‐oxidation to sulfone was ever observed.magnified image
• Aerobic Organocatalytic Oxidation of Aryl Aldehydes: Flavin Catalyst Turnover by Hantzsch’s Ester
  作者：Shuai Chen、Frank W. Foss

  DOI：10.1021/ol302479b

  日期：2012.10.5

  The first Dakin oxidation fueled by molecular oxygen as the terminal oxidant is reported. Flavin and NAD(P)H coenzymes, from natural enzymatic redox systems, inspired the use of flavin organocatalysts and a Hantzsch ester to perform transition-metal-free, aerobic oxidations. Catechols and electron-rich phenols are achieved with as low as a 0.1 mol % catalyst loading, 1 equiv of Hantzsch ester, and O-2 or air as the stoichiometric oxidant source.