Formal [4 + 1] Annulation of α-Arylhydrazonoketones and Dimethylsulfoxonium Methylide: One-pot Synthesis of Substituted Pyrazoles and Dihydropyrazoles.
A formal [4 + 1] annulation of readily available α-arylhydrazonoketones and trimethylsulfoxonium iodide in the presence of cesium carbonate is described involving a sequential Corey-Chaykovsky reaction and intramolecular nucleophilic cyclization process. Substituted pyrazoles were obtained exclusively from the reactions of α-arylhydrazono-β-oxo-amides and trimethylsulfoxonium iodide in moderate to good yields, whereas the reactions of α-arylhydrazono-β-oxo-ketone/α-arylhydrazono- β-oxo-ester afforded the corresponding dihydropyrazoles in good yields.
Key Laboratory of Synthetic Rubber, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, 130022, China.|University of Chinese Academy of Sciences , Beijing 100039, China.
Qian
Q
Zhang
Key Laboratory of Synthetic Rubber, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, 130022, China.
Mangfei
M
Yu
Key Laboratory of Synthetic Rubber, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, 130022, China.|University of Chinese Academy of Sciences , Beijing 100039, China.
Jingwen
J
Yuan
Key Laboratory of Synthetic Rubber, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, 130022, China.
Rui
R
Zhang
Key Laboratory of Synthetic Rubber, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, 130022, China.
Yongjiu
Y
Liang
Department of Chemistry, Northeast Normal University , Changchun 130024, China.
Jiamei
J
Tian
Key Laboratory of Synthetic Rubber, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, 130022, China.
Dewen
D
Dong