Artificial nonheme iron and manganese oxygenases for enantioselective olefin epoxidation and alkane hydroxylation reactions

The development of sustainable enantioselective olefin epoxidation and alkane oxidation reactions under environmentally friendly conditions is an ultimate goal that has long been pursued in chemistry. Excellent examples are naturally occurring monooxygenases, which are able to catalyze a variety of biological oxidation reactions using molecular oxygen (O₂) that afford high chemo-, regio-, and/or stereoselectivities. Inspired by the oxidation reactions of iron-containing monooxygenases, substantial efforts have been made towards the development of efficient catalysis for the enantioselective oxidation of hydrocarbons using bioinspired nonheme iron and manganese catalysts under mild conditions. In this review, we describe synthetic models that functionally mimic these monooxygenases. There are a large number of nonheme iron and manganese complexes that can epoxidize olefins with high enantioselectivities, whereas only a few examples are reported for nonheme iron- and manganese-catalyzed enantioselective oxidation of inert C(sp³)–H bonds. In addition to its great achievement for synthetic applications, mechanistic studies in biomimetic oxidation systems have also been intensively investigated, providing important insights into the understanding of the nature of active oxidants and the formation of the intermediates via O[sbnd]O bond activation and the design of more elegant biomimetic oxidation catalysts. Thus, these bioinspired nonheme iron and manganese complexes used as catalysts in the enantioselective C[dbnd]C epoxidation and aliphatic C(sp³)–H oxidation are the focus of discussion in this review.