Divergent Synthesis of 3,5‐Disubstituted Pyrazoles and α, β ‐Alkynic Hydrazone from Diarylpropynones and Carbazates

Abstract Yb(OTf) 3 catalyzed synthesis of pyrazoles by cyclization of 1,3‐diarylpropynones with carbazates was reported. In the presence of K 2 S 2 O 8 /TBAI as catalyst, α , β ‐alkynic hydrazone was obtained through the reactions from the same starting materials in up to 97% yields. Mechanistic studies indicated that propargyl hydrazone was not involved in pyrazole formation. The aggregation‐induced emission (AIE) characteristics of the pyrazoles were explored, demonstrating potential applications in the luminophoric materials.