N-Heterocyclic Carbene-Catalyzed [4+2] Cycloaddition of Salicylaldehydes with Pyrazole-4,5-diones for the Synthesis of Spiroketal-Pyrazolones
Xiaomei Wang, Yan Liu, Shiwu Li, Zhifei Zhao
Chinese Journal of Organic Chemistry . 2025, (1): 267 -275 .  DOI: 10.6023/cjoc202406005