Assembly of 1,3-diaryl-1H-pyrazoles via base-mediated [3 + 2] cycloaddition
Tenglong Xu1, Zimei Zhong1, Jianwei Yan1
1College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, 311121, P. R. China. wangaf@hznu.edu.cn.
None:
1,3-Diaryl-1H-pyrazoles, serving as privileged heterocyclic scaffolds, demonstrate significant application potential in pharmaceutical development, functional materials, and agrochemical industries. This study presents a synthetic strategy based on [3 + 2] cycloaddition, achieving efficient construction of 1,3-diaryl-1H-pyrazoles. A novel transition metal-free protocol was established through base-catalyzed intermolecular annulation of hydrazones with vinyl sulfoxides, followed by oxidation. The reaction system exhibited excellent substrate generality and demonstrated successful gram-scale synthesis. Subsequent investigations into synthetic applications further confirmed the methodology's practicality and scalability.
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