Formal [4 + 1] annulation of fluorinated sulfonium salt with cyclic unsaturated imines to access CF-substituted pyrroles.

Formal [4 + 1] annulation of easily available fluorinated sulfonium salt with cyclic unsaturated imines has been successfully developed. A structurally diverse set of CF-substituted dihydropyrroles was efficiently constructed in acceptable to excellent yields with excellent diastereoselectivities. The resulting CF-containing dihydropyrroles from this transition metal-free strategy could be easily transformed to pyrroles in good yields under basic conditions.