Mechanistic Understanding on Iron‐Catalyzed CH Activation

Abstract Modern synthetic chemistry has explored the applicability of more abundant and less toxic transition metals based on their reactivity towards CH functionalization reactions despite their lower catalytic performance compared to noble‐metal catalysis. However, a strong understanding of the reaction mechanism is required to make a rational design of a catalytic system without the need to test a wide variety of conditions libraries with poor results. Mechanistic studies are not trivial, and comprehensive experimental and computational data is preferred to draw a complete mechanistic scenario for each catalytic system. In this sense, during the last decade, iron‐based catalysts have presented very prominent results in the CH functionalization arena. Nevertheless, there is plenty of room to improve their catalytic performance to reach activities to the noble metal‐based catalysts. Thus, in order to give an overview to the reader, we focus this review on the recent articles digging into mechanistic aspects from different perspectives covering spectroscopic analyses of possible reaction intermediates, kinetic, thermodynamic, and theoretical studies on iron‐based CH functionalizations following inner‐sphere mechanisms. Hence, the critical parameters and conditions are summarized to clarify the iron catalysts' mode of action on the CH activation to enhance their catalytic performances and look for more sustainable catalytic transformations with this metal.