The decarboxylation mechanism of the intermediate compound isatin-imino acid 5a to form ylides 6.

 
 
  Part of: Sammor MS, Habashneh AY, Al-Sha'er MA, Bardaweel SK, El‐Abadelah MM (2025) Novel spirooxindole compounds as anticancer agents: targeting Plk4 kinase through design, synthesis, and molecular docking. Pharmacia 72: 1-13. https://doi.org/10.3897/pharmacia.72.e149240