Metal‐Free, Persulfate‐Mediated Oxidative Radical CH Functionalizations

Abstract

Carbon–carbon/carbon–heteroatom bond formation via oxidative CH functionalization is a novel approach which shifts the focus from the standard organic synthesis involving selective reactions at functional groups. The new logic relies on the controlled functionalization of specific CH bonds, even in the presence of supposedly more reactive functional groups and is currently a heavily explored topic. Peroxydisulfate oxidants have risen as an economical and readily available choice of inorganic oxidant, catalyzing a wide range of oxidative transformations, varying from laboratory experiments to industrial processes. The current article provides a comprehensive analysis of significant oxidative transformations brought about by persulfates, with or without the aid of any additives, under transition‐metal‐free conditions. The report focuses on the critical assessment of the reactions involved, the explored substrate scopes, and the underlying mechanisms. This article can be a useful guide for the organic chemists interested in the expedient synthesis of new chemical entities, formulation of mechanistic manifolds involving the sulfate radical anion, or designing of novel oxidative transformations. However, a thorough understanding of the unsolved mechanisms can further reinforce the field.