Recent Progress in Organocatalyzed Epoxidation and Reaction of Epoxide

Abstract: Epoxides serve as highly versatile intermediates in the synthesis of diverse organic motifs. Their inherent ring strain makes them susceptible to nucleophilic attack, underscoring their utility in the synthesis of many natural products, bioactive molecules, and polymers. With the development of new organocatalysts, a broad range of olefins can now be epoxidized using green oxidants such as H2O2 and O2. Growing environmental awareness of the presence of metals in bioactive molecules has provided fresh impetus for the development of environmentally friendly epoxidation methods using small-molecule catalysts and green oxidants. As organocatalytic methods have matured, they have transitioned from academic curiosities to practical technologies for the synthesis of active pharmaceutical ingredients, natural products, and enantiomerically enriched bioactive molecules. Their convergence of stereochemical control, operational simplicity, and sustainability has enabled reliable scale-up in process settings while meeting stringent quality, safety, and regulatory requirements. This mini-review aims to consolidate several outstanding studies on organocatalyzed epoxidation. It also highlights the significance of various organocatalysts in these reactions. It begins with a brief overview of the topic, emphasizing the green and sustainable aspects of organocatalysis and its advantages over metal-catalyzed epoxidation. Organocatalytic epoxidation offers tangible benefits to researchers developing complex molecules. Subsequently, recent research findings on the use of organocatalysts in epoxidation are summarized, along with mechanistic studies. These studies not only deepen our understanding of reaction mechanisms but also inform the design of new catalysts and methodologies. Reaction mechanisms are presented concisely, allowing readers to grasp the underlying similarities across them. Finally, the review discusses the practical utility of organocatalysts in the synthesis of valuable organic compounds. The concluding section outlines current challenges, limitations, and prospects for organocatalysis in epoxidation.