title: Oxidation of alkane and alkene moieties with biologically inspired nonheme iron catalysts and hydrogen peroxide: from free radicals to stereoselective transformations.
abstract: The selective oxidation of hydrocarbons is a challenging reaction for synthetic chemists, but common in nature. Iron oxygenases activate the O-O bond of dioxygen to perform oxidation of alkane and alkenes moieties with outstanding levels of regio-, chemo- and stereoselectivity. Along a bioinspired approach, iron coordination complexes which mimic structural and reactivity aspects of the active sites of nonheme iron oxygenases have been explored as oxidation catalysts. This review describes the evolution of this research field, from the early attempts to reproduce the basic reactivity of nonheme iron oxygenases to the development of effective iron oxidation catalysts. The work covers exclusively nonheme iron complexes which rely on H2O2or O2as terminal oxidants. First, it delineates the key steps and the essential catalyst design principles required to activate the peroxide bond at nonheme iron centers without (or at least minimizing) the release of free-diffusing radicals. It follows with a critical description of the mechanistic pathways which govern the reaction between iron complexes and H2O2to generate the oxidizing species. Eventually, the work presents a state-of-the-art report on the use of these catalysts in aliphatic C-H oxidation, olefin epoxidation and alkene syn-dihydroxylation, under substrate-limiting conditions. A special focus is given on the main strategies elaborated to tune catalyst activity and selectivity by modification of its structure. The work is concluded by a concise discussion on the essential progresses of these oxidation catalysts together with the challenges that remain still to be tackled.
authors.affiliation: Departament de Química and Institut de Química Computacional i Catàlisi (IQCC), Universitat de Girona, Campus Montilivi, 17071, Girona, Catalonia, Spain.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Olivo
authors.affiliation: Departament de Química and Institut de Química Computacional i Catàlisi (IQCC), Universitat de Girona, Campus Montilivi, 17071, Girona, Catalonia, Spain.
authors.forename: Olaf
authors.initials: O
authors.lastname: Cussó
authors.affiliation: Departament de Química and Institut de Química Computacional i Catàlisi (IQCC), Universitat de Girona, Campus Montilivi, 17071, Girona, Catalonia, Spain.
authors.forename: Margarida
authors.initials: M
authors.lastname: Borrell
authors.affiliation: Departament de Química and Institut de Química Computacional i Catàlisi (IQCC), Universitat de Girona, Campus Montilivi, 17071, Girona, Catalonia, Spain. miquel.costas@udg.edu.
authors.forename: Miquel
authors.initials: M
authors.lastname: Costas
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D032701:Biomimetics / Q000379:methods*; D002384:Catalysis; D005609:Free Radicals / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D013237:Stereoisomerism
chemical_list: D000473:Alkanes; D000475:Alkenes; D005609:Free Radicals; D006861:Hydrogen Peroxide; D007501:Iron
keywords: Bioinspired catalysis; Hydrogen peroxide; Nonheme iron; Oxygenases