Synthesis
DOI: 10.1055/a-2773-5093
Paper

Amine-Catalyzed [3+3] Annulation Reaction Between α-Alkylidene Pyrazolinones and α,β-Unsaturated Aldehydes for the Construction of Spiropyrazolones

Authors

  • Zhuo-Yi Wang

    1   School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, China (Ringgold ID: RIN70586)
  • Fei Chen

    1   School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, China (Ringgold ID: RIN70586)
  • Chunbo Bo

    1   School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, China (Ringgold ID: RIN70586)
  • Min Li

    1   School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, China (Ringgold ID: RIN70586)
  • Ning Liu

    1   School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, China (Ringgold ID: RIN70586)
  • Zhi-Hong Du

    1   School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, China (Ringgold ID: RIN70586)

Supported by: National Natural Science Foundation of China 22201186
Supported by: Science and Technology Program of XPCC 2025DA044
Supported by: Tianchi Talent Project of Xinjiang Uygur Autonomous Region

A secondary amine-catalyzed [3+3] annulation of α-alkylidene pyrazolinones with α,β-unsaturated aldehydes was reported. Conducted in ethanol with acetic acid as an additive, the reaction proceeds at room temperature under a nitrogen atmosphere, affording a series of spirocyclohexane pyrazolinone compounds in high yields (up to 96%) and excellent diastereoselectivity (dr up to 99:1). Gram-scale amplification experiments show that the yield and diastereoselectivity remain uncompromised, highlighting the significant application potential of this synthetic protocol. HR-MS-based mechanistic studies confirm that the reaction follows a Michael-Aldol cascade pathway.



Publication History

Received: 12 November 2025

Accepted after revision: 15 December 2025

Accepted Manuscript online:
16 December 2025

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