Recent Trends and Prospects in Homogeneous Manganese-Catalysed Epoxidation

Epoxidation of alkenes is a significant reaction in organic chemistry due to its opportunities in producing compounds of biochemical interest. Catalytic epoxidation with first-row transition elements has gained attention in the latest years wherein manganese based catalysts stand superior by satisfying numerous principles of green chemistry. In this review, we have summarized the recent developments in olefin epoxidation using homogeneous manganese catalysts. Manganese complexes with porphyrin, Schiff base, salen, and other non-heme ligands made efficient catalytic systems during the last five years. Notably, we witnessed greener approaches in recent reports wherein photo-catalysis is a promising strategy. We anticipate that the review will benefit the researchers to get a better understanding of the reaction and to choose the best catalysts for their reactions. 1. Introduction 2. Mn-II-Catalysed Epoxidation 2.1. Mn-II-Salt 2.2. N-4-Tetradentate Complexes 2.3. N2O2-Tetradentate Complex 2.4. Higher-Dentate Complexes 3. Mn-III-Catalysed Epoxidation 3.1. O-2-Bischelate Complexes 3.2. N-2-Bischelate Complexes and N,O-Bischelate Complexes 3.3. N2O2-Tetradentate Complexes 3.4. N-4-Tetradentate Complexes 3.5. Higher-Dentate Complexes 4. Mn(IV-)Catalysed Epoxidation 5. MnV-Catalysed Epoxidation 6 Applications 7. Conclusions

Automated summary

Epoxidation of alkenes is an important reaction in organic chemistry with significant potential in producing biochemically relevant compounds. Recent studies have focused on catalytic epoxidation using homogeneous manganese catalysts, particularly with porphyrin, Schiff base, Salen, and other ligands, showing advantages in green chemistry. The use of greener approaches, such as photo-catalysis, has been highlighted in recent reports, aiming to provide researchers with a better understanding of the reaction and catalyst selection.