Substituent effect in iron-catalysed C-H bond oxidation

The search for efficient and selective methods to oxidize C-H bonds has been a longstanding goal in organic chemistry. However, it is less than 6 years that this goal managed to become a useful tool in synthetic chemists hands by the use of nonheme iron catalysts. One of the most efficient catalytic systems prepared so far is White’s complex,1 reported in Figure 1 (R=H, the first structure on the left). With the aim at shedding some light on the mechanism by which this system works, we prepared the three substituted iron (II) PDP complexes shown below. The chosen substituents allow a wide investigation of the electronic effects on the catalytic efficiency of the system. The results obtained in the oxidation of C-H bonds of some non-activated hydrocarbons substrates will be shown together with the synthetic route and a full characterization of the new iron complexes.