A Direct Silver‐Catalyzed Three‐Component Approach to Trifluoromethylated Cyanopyrazoles and Cyanopyrazolines

A three‐component strategy for the synthesis of an important class of trifluoromethylated cyanopyrazoles from aldehydes, malononitrile and trifluorodiazoethane is reported. This approach involves a domino Knoevenagel condensation/1,3‐dipolar cycloaddition/dehydrocyanation process. Surprisingly, the use of cyanoacetate in place of malononitrile resulted in the formation of trifluoromethylated cyanopyrazolines. The protocol provides access to a wide variety of trisubstituted pyrazoles and pyrazolines thus expanding the chemical space for these structural units.