Anodic fluorination of flavone and 6-chloroflavone was carried out using Et3N ⋅ 3 HF and Et4NF ⋅ 4 HF as supporting electrolytes. The former supporting electrolyte provided 3-monofluorinated flavones 2 preferentially while the latter one gave 2,3-difluorinated flavones 3 predominantly. It was also found that the yields of 2 increased significantly at a higher temperature as 30 °C. Furthermore, it was confirmed that 2 was formed by dehydrofluorination of 3 with free Et3N in Et3N ⋅ 3 HF.
以 Et3N ⋅ 3 HF 和 Et4NF ⋅ 4 HF 作为支撑电解质,对
黄酮和
6-氯黄酮进行了阳极
氟化。前一种支持电解质优先提供 3-单
氟黄酮 2,而后一种支持电解质主要提供 2,3-二
氟黄酮 3。研究还发现,在 30 ℃ 的高温下,2 的产率显著增加。此外,还证实 2 是通过 3 与游离 Et3N 在 Et3N ⋅ 3 HF 中的脱氢
氟化反应生成的。