Selective Anodic Fluorination of Flavones
31 December 2000 (online)
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.
flavone - 6-chloroflavone - electrochemical fluorination - anodic oxidation - regioselectivity