Organic Chemistry Portal



Palladium-Catalyzed Cascade Carbonylative Synthesis of 1,2,4-Triazol-3-ones from Hydrazonoyl Chlorides and NaN3

Shiying Du, Wei-Feng Wang, Yufei Song, Zhengkai Chen* and Xiao-Feng Wu*

*Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China; Universitšt Rostock, Albert-Einstein-Straβe 29a, 18059 Rostock, Germany, Email:,

S. Du, W.-F. Wang, Y. Song, Z. Chen, X.-F. Wu, Org. Lett., 2021, 23, 974-978.

DOI: 10.1021/acs.orglett.0c04167 (free Supporting Information)

see article for more reactions


A Pd-catalyzed three-component carbonylative reaction provide structurally diverses 3H-1,2,4-triazol-3-ones in good yields from hydrazonoyl chlorides and NaN3 through a cascade carbonylation, acyl azide formation, Curtius rearrangement, and intramolecular nucleophilic addition sequence. Benzene-1,3,5-triyl triformate (TFBen) has been used as a solid and convenient CO surrogate.

see article for more examples

proposed mechanism

Synthesis of 3H-1,2,4-Triazol-3-ones via NiCl2-Promoted Cascade Annulation of Hydrazonoyl Chlorides and Sodium Cyanate

S. Du, Z. Yang, J. Tang, Z. Chen, X.-F. Wu, Org. Lett., 2021, 23, 2359-2363.

Key Words

3H-1,2,4-triazol-3-ones, multicomponent reactions, Curtius rearrangement

ID: J54-Y2021