Theoretical Studies on Iron Carbene‐Catalyzed Olefin Metathesis and Agostic Interactions in Complexes

First‐row transition metals, as substitutes for traditional transition metals such as Ru and Mo, are capable of catalyzing olefin metathesis. Iron‐based catalysts have attracted widespread attention due to their cost‐effectiveness and low toxicity. Herein, we theoretically investigate the metathesis of norbornadiene and its derivatives catalyzed by iron carbene complexes. To evaluate the reaction characteristics, both singlet and triplet states of the catalysts and intermediates are considered. The results indicate that the singlet‐state metallacyclobutanes have lower energy and involve interactions. Further analysis demonstrates that the interactions are C─H···Fe agostic interactions, which may be related to the stability of the intermediates.