Selective Electrochemical Fluorodesulfurization of Benzo- and Pyrido-Fused Oxazine Derivatives Using Ex-cell Halogen Mediators
作者:Toshio Fuchigami、Bin Yin、Shinsuke Inagi
DOI:10.1055/s-0030-1260085
日期:2011.8
Although the direct anodic fluorination of 3-phenyl-2H-1,4-benzoxazine was not very effective, the fluorodesulfurization of 3-aryl-2-(phenylsulfanyl)-2H-1,4-benzoxazines using various anodically generated halogen mediators in the presence of triethylamine tris(hydrogen fluoride) by an ex-cell method efficiently and selectively provided the corresponding monofluorinated products. In sharp contrast, in-cell halogen mediators did not work well. Furthermore, the selective fluorodesulfurization of pyrido[3,2-b][1,4]oxazine derivatives was also successfully carried out using the same ex-cell method to provide the corresponding monofluorinated products in moderate yields.
虽然 3-苯基-2H-1,4-苯并噁嗪的直接阳极氟化效果不佳,但在三乙胺三(氟化氢)存在下,使用各种阳极生成的卤素媒介物,采用外室法对 3-芳基-2-(苯硫基)-2H-1,4-苯并噁嗪进行氟化脱硫,却能高效且有选择性地提供相应的单氟化产物。与此形成鲜明对比的是,池内卤素介质的效果并不理想。此外,使用相同的外室法还成功地对吡啶并[3,2-b][1,4]恶嗪衍生物进行了选择性氟化脱硫,以中等产率提供了相应的单氟化产物。