Oxygenation of olefin, N-dealkylation of tertiary amine, oxidation of sulfide, and oxidative cleavage of ether bond were conducted with tetraphenylporphyrinatoiron(III) (Fe3+TPPCl), NaBH4, Me4N. OH, and molecular dioxygen in benzene — methanol solution. Fe3+TPPCl, NaBH4, and molecular dioxygen were essential for these reactions and the yields were decreased when Me4N OH was absent. Olefins were converted to alcohols, which were not produced from the corresponding epoxides under the same conditions. In styrene oxygenation, an electron-donating substituent on the substrate decreased the reactivity, whereas in N,N-dimethylaniline demethylation, it enhanced the reactivity. Despite the use of the same reagents, the key intermediates of these two reactions are different. Fe2+TPP —σ-alkyl complexes produced from Fe3+TPPCl, olefin, and NaBH4 were identified as intermediates under anaerobic conditions. Fe2+TPP — σ-alkyl complex reacted with molecular dioxygen to give oxygenated products. Examination of the relative reactivities of p-substituted N,N-dimethylanilines in the NaBH4 reaction system revealed first, that the demethylation proceeded via one-electron abstraction, and second, that the reactive species of the demethylation reactions seems to be an iron-oxenoid.
ASJC Scopus subject areas
- Drug Discovery