Efficient Preparation of 3-Fluoropyrrole Derivatives

Efficient Preparation of 3-Fluoropyrrole Derivatives

Noble N-substituted-3-fluoropyrroles derivatives were prepared from new precursor via ring formation. The addition reaction of ethyl iododifluoroacetate to vinyl trimethylsilane under the Cu(0) catalyst resulted in the formation of ethyl-2,2-difluoro-4-iodo-4-(trimethylsilyl)butanolate, which reacted with diisobutylaluminium hydride at $-30^{\circ}C$ to yield 2,2-diflouro-4-iodo-4-(trimethylsilyl)butanal. Finally, a series of N-substituted-3-fluoropyrrole derivatives were synthesized by the reaction of 2,2-diflouro-4-iodo-4-(trimethylsilyl)butanal with $NH_4OH$ or primary amines followed by reaction with KF solution.