Pentafluorohalobenzene (C6F5X) as Iodine or Bromine Transfer Reagents for Synthesis of Disubstituted Pyridines
Rajasekar Reddy Annapureddy1, Maksim Vasilev1, Nageswara Rao Kalikinidi1
1TCG GreenChem, Inc. 701 Charles Ewing Blvd, Ewing, New Jersey 08628, United States.
Abstract:
We report pentafluorohalobenzene (C6F5I and C6F5Br) as an iodine or bromine transfer reagent for the generation of both electron-rich and electron-poor (hetero)aryl iodides and bromides with excellent chemo/regio selectivity in up to 95% yields. Continuous flow synthesis proved to be advantageous for this transformation. The iodine or bromine transfer occurs through treatment with in situ-generated (hetero)aryl Grignard reagents derived from aryl halides with C6F5I or C6F5Br. The resulting iodo- and chloro/bromo-pyridines were further transformed into bis-substituted pyridines through subsequent chemoselective coupling reactions.
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