A comprehensive mechanistic study by means of complementary experimental and computational approaches of the exo‐cyclohydroamination of primary aminoalkenes mediated by the recently reported β‐diketiminatoiron(II) complex B is presented. Kinetic analysis of the cyclisation of 2,2‐diphenylpent‐4‐en‐1‐amine (1 a) catalysed by B revealed a first‐order dependence of the rate on both aminoalkene and catalyst concentrations and a primary kinetic isotope effect (KIE) (k_H/k_D) of 2.7 (90 °C). Eyring analysis afforded ΔH^≠=22.2 kcal mol⁻¹, ΔS^≠=−13.4 cal mol⁻¹ K⁻¹. Plausible mechanistic pathways for competitive avenues of direct intramolecular hydroamination and oxidative amination have been scrutinised computationally. A kinetically challenging proton‐assisted concerted N−C/C−H bond‐forming non‐insertive pathway is seen not to be accessible in the presence of a distinctly faster σ‐insertive pathway. This operative pathway involves 1) rapid and reversible syn‐migratory 1,2‐insertion of the alkene into the Fe−N_amido σ bond at the monomer {N^N}Fe^II amido compound; 2) turnover‐limiting Fe−C σ bond aminolysis at the thus generated transient {N^N}Fe^II alkyl intermediate and 3) regeneration of the catalytically competent {N^N}Fe^II amido complex, which favours its dimer, likely representing the catalyst resting state, through rapid cycloamine displacement by substrate. The collectively derived mechanistic picture is consonant with all empirical data obtained from stoichiometric, catalytic and kinetics experiments.

中文翻译：

---

β-二酮基亚铁（II）催化的伯氨基烯烃加氢胺化的实验和计算机理研究

通过互补试验和的计算方法的装置的综合机理研究外由最近报道β-diketiminatoiron介导的初级aminoalkenes的-cyclohydroamination（II）络合物乙呈现。由B催化的2,2-二苯基五-4-烯-1-胺（1 a）环化的动力学分析表明，速率对氨基烯烃和催化剂浓度的一级依赖性以及一次动力学同位素效应（KIE） （k _H / k _D）为2.7（90°C）。得到的Eyring分析Δ ħ ^≠ = 22.2千卡摩尔^-1，Δ小号^≠ = -13.4 CAL摩尔^-1  K ^-1。直接分子内加氢胺化和氧化胺化的竞争途径的合理的机械途径已通过计算进行了仔细研究。在存在明显较快的σ插入途径的情况下，动力学上质子辅助的协调一致的N / C / H键形成非插入途径被认为是不可及的。此手术途径涉及1）快速和可逆的顺式烯烃进入Fe-N系列的-migratory 1,2-插入_酰氨σ键在单体{N 1，N}的Fe ^II酰胺化合物; 2）在由此产生的瞬态{N ^ N} Fe ^II烷基中间体上限制营业额的Fe-Cσ键氨解和3）催化活性{N ^ N} Fe ^II的再生通过快速被底物取代环胺，有利于其二聚体的酰胺基络合物，可能代表催化剂的静止状态。集体得出的机理图与从化学计量，催化和动力学实验获得的所有经验数据是一致的。