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

Abstract 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(1 H )‐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(1 H )‐ones and monofluoroquinoxalin‐2(1 H )‐ones in 51–92% yields. magnified image