Controlling Iron-Catalyzed Oxidation Reactions: From Non-Selective Radical to Selective Non-Radical Reactions

A study was conducted to demonstrate the relationship between the absolute proton concentration (pH value), change of pH value, and catalytic performance in important iron-catalyzed selective oxidation reactions. As per this hypothesis, the high selectivity should be independent of the pH value of the buffer and the nature of the buffer system. It clearly shows that an increased proton concentration led to higher catalyst activity and a small change of pH value during the reaction is responsible for improved selectivity. Essentially, iron oxo and radical pathways in iron-catalyzed redox reactions are switchable using the change of pH value as an on-off. The study also suggests that it is of original importance in oxidation chemistry and it should provide useful inspiration to rethink the mechanism of iron-catalyzed reactions.