Synthesis of 2‐Alkenyl‐4 H ‐3,1‐Benzoxazin‐4‐Ones through HFIP‐Mediated Decarboxylative [4+2]‐Annulation of Isatoic Anhydrides with Cyclopropenones under Silver Catalysis

We herein describes an HFIP‐mediated [4+2]‐cycloaddition reaction from simple and easily available isatoic anhydrides and cyclopropenones under silver catalysis. This transformation involves the tandem decarboxylative esterification, intermolecular addition, intramolecular substitution, small ring opening and isomerization processes, which allows the rapid assembly of versatile 2‐diarylalkenyl‐4 H ‐3,1‐benzoxazin‐4‐ones. magnified image