Predicting Dinitrogen Activation via Transition Metal Involved [4 + 2] Cycloaddition Reaction
As the strongest triple bond in nature, the N≡N triple bond activation has always been a challenging project in chemistry. On the other hand, since the award of the Nobel Prize in Chemistry in 1950, Diels‐Alder reaction has served as a powerful and widely applied tool in the synthesis of natural products and new materials. However, the application of Diels‐Alder reaction to dinitrogen activation remains less developed. Here we first demonstrate that a transition metal involved [4 + 2] Diels‐Alder cycloaddition reaction could be used to activate dinitrogen without an additional reductant by density functional theory calculations. Further study reveals that such a dinitrogen activation by a 1‐metalla‐1,3‐dienes screened out from a series of transition metal complexes (38 species) according to the effects of metal center, ligand, and substituents can become favorable both thermodynamically (with an exergonicity of 28.2 kcal mol‐1) and kinetically (with an activation energy as low as 13.8 kcal mol‐1). Our findings highlight an important application of Diels‐Alder reaction in dinitrogen activation, inviting experimental chemists’ verification.