Nonheme iron complex-catalyzed efficient alcohol oxidation by t-BuOOH with N-hydroxyphthalimide (NHPI) as co-catalyst: Implication of high valent iron-oxo species
| Autor: | Sun Young Lee, Kwon Hee Bok, Cheal Kim, Seul Ah Lee, Myoung Mi Lee, Jeong Mi Bae, Jinheung Kim |
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| Rok vydání: | 2016 |
| Předmět: |
High-valent iron
010405 organic chemistry Chemistry 010402 general chemistry 01 natural sciences Heterolysis Medicinal chemistry 0104 chemical sciences Catalysis Inorganic Chemistry chemistry.chemical_compound Hammett equation Catalytic oxidation Alcohol oxidation Materials Chemistry tert-Butyl hydroperoxide Organic chemistry Physical and Theoretical Chemistry Bond cleavage |
| Zdroj: | Inorganica Chimica Acta. 451:8-15 |
| ISSN: | 0020-1693 |
| DOI: | 10.1016/j.ica.2016.06.038 |
| Popis: | Two iron catalysts ([Fe(bpc)Cl2][Et4N] (1a) and [Fe(Me2bpb)Cl2][Et3NH] (1b)) displayed efficient catalysis in oxidation of various alcohols to the corresponding carbonyl products using t-BuOOH as an oxidant in the presence of N-hydroxyphthalimide (NHPI) under mild conditions. 1a having an electron-withdrawing group showed a little better catalytic activity than that of 1b with an electron-donating group. The mechanistic studies through Hammett plot, deuterium isotope effect, and the use of 2-methyl-1-phenylprop-2-yl hydroperoxide (MPPH) as a mechanistic probe suggested that the reactive oxidants responsible for the alcohol oxidation possibly involved FeIV O species, alkoxy radical (RO ), and phthalimide N-oxyl radical (PINO ). On the other hand, the presence of imidazole increased the heterolytic cleavage of Fe-OOR intermediate to form FeV O species and accelerated its O O bond cleavage rate. In particular, the formation of FeV O intermediate via the heterolytic cleavage of Fe-OOR species in the presence of imidazole in the catalytic oxidation systems of nonheme iron complexes with t-BuOOH was substantialized, for the first time, to the best of our knowledge. |
| Databáze: | OpenAIRE |
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