A base-promoted 3 + 3 annulation of trifluoromethyl alkenes with N -substituted pyrrole-2-carboxaldehydes has been developed for the synthesis of fluorinated 4 H -pyran derivatives. This reaction involves the consecutive cleavage of C–F bonds in the trifluoromethyl and the formation of new chemical bonds without the use of a catalyst. Additionally, this methodology features mild reaction conditions and a good functional group tolerance.
Liu et al. (Sun,) studied this question.