Green chemistry spotlight: metal-free organic transformations mediated by potassium persulfate

Potassium persulfate (K₂S₂O₈) has been used for the construction of carbon-carbon (C-C) and carbon-heteroatom (C-P/C-N/C-S/C-Se) bonds through metal-free oxidative transformations. This inexpensive oxidant has garnered significant attention in recent years as it is a green alternative for oxidative transformations. This review presents an update on the applications of potassium persulfate (K₂S₂O₈) in various transformations in the last six years (2018-2024). The key advancements in metal-free reactions driven by K₂S₂O₈ are highlighted, and critical discussions on their limitations are incorporated. Herein, this review focuses on presenting a perspective to organic chemists, encouraging the strategic development of unprecedented K₂S₂O₈-promoted oxidative methodologies by identifying the research gaps. Furthermore, it offers mechanistic insights into the underlying free-radical pathways of the reaction mechanism in detail.