Copper(I)-Catalyzed Interrupted Click Reaction with TMSCF3: Synthesis of 5-Trifluoromethyl 1,2,3-Triazoles

We herein describe a Cu(I)-catalyzed interrupted click reaction, using (trifluoromethyl)trimethylsilane (TMSCF3) as a nucleophilic CF3 source, to synthesize 5-trifluoromethyl 1,2,3-triazoles in one step from readily available terminal alkynes and azides. The reaction shows complete regioselectivity, broad substrate scope, and good functional group tolerability. The application of the reaction has been demonstrated in the synthesis of a trifluoromethylated analog of antiepileptic drug rufinamide.