HFIP‐Catalyzed Mannich Reaction: Divergent Synthesis of Difluoro‐Substituted 3,4‐Dihydroquinoxalin‐2(1H)‐ones and Monofluoroquinoxalin‐2(1H)‐ones.

Hexafluoroisopropanol (HFIP) has been extensively applied in organic synthesis as a versatile reaction media. However, the application of HFIP as an catalyst in organic synthesis has been rarely studied. Presented here, is the example of HFIP‐catalyzed Mannich‐type reaction between quinoxalin‐2(1H)‐ones and difluoroenoxysilanes. The developed protocol tolerates various substituents under mild reaction conditions, providing a divergent approach to the construction of difluoro‐substituted 3,4‐dihydroquinoxalin‐2(1H)‐ones and monofluoroquinoxalin‐2(1H)‐ones in 51–92% yields. [ABSTRACT FROM AUTHOR]