Synthesis of Trifluoromethyl‐Containing 2,3‐Dihydrobenzofurans via a Formal [4+1] Annulation of In‐situ Generated o‐Quinone Methides and CF3−Imidoyl Sulfoxonium Ylides

Abstract A metal‐free [4+1] annulation of in‐situ generated ortho ‐quinone methides ( o ‐QMs) and CF 3 −imidoyl sulfoxonium ylides (TFISYs) has been achieved under mild conditions, which provides a facile and straightforward access to a variety of trifluoromethyl‐containing 2,3‐dihydrobenzofurans in moderate to excellent yields.