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Exploring the factors controlling the mechanism and the high stereoselectivity of the polar [3+2] cycloaddition reaction of the N,N'-cyclic azomethine imine with 3-nitro-2-phenyl-2H-chromene. A molecular electron density theory study
Chemistry of Heterocyclic Compounds ( IF 1.4 ) Pub Date : 2023-04-24 , DOI: 10.1007/s10593-023-03174-2
Sabir Messaadia , Abdelmalek Khorief Nacereddine , Abdelhafid Djerourou

A molecular electron density theory study of the [3+2] cycloaddition reaction of 5-oxo-2-(phenylmethylidene)pyrazolidin-2-ium-1-ide, a simple azomethine imine, with 3-nitro-2-phenyl-2H-chromene was carried out at the B3LYP/6-311G(d,p) computational level in order to unravel the origin of the stereoselectivity experimentally observed. Electron localization function and natural population analysis showed that the azomethine imine is a zwitterionic three-atom component. Analysis of the conceptual density functional theory reactivity indices indicates that azomethine imine is a strong nucleophile, while 3-nitro-2-phenyl-2H-chromene is a good electrophile, which accounts for a polar process confirmed by the high global electron density transfer values. The Parr function indices explain well the experimentally obtained ortho regioselectivity. Analysis of the energy profiles of the possible reactive pathways in gas phase and in solution of i-PrOH points to high exo stereoselectivity and complete ortho regioselectivity of the reaction in excellent agreement with the experimental findings. Analysis of the transition state structures indicates a very asynchronous molecular mechanism for the favored orthoregioisomeric reaction channels. Analysis using noncovalent interactions, quantum theory of atoms in molecules, and independent gradient model based on Hirshfeld distribution indicates that the presence of several hydrogen bonds and van der Waals intermolecular noncovalent interactions are the factors favoring the ortho-exo selectivity. The bonding evolution theory study of the most favorable pathway reveals a two-stage one-step molecular mechanism.



中文翻译:

探索 N,N'-环偶氮甲亚胺与 3-硝基-2-苯基-2H-色烯的极性 [3+2] 环加成反应的控制机理和高立体选择性的控制因素。分子电子密度理论研究

5-oxo-2-(phenylmethylidene)pyrazolidin-2-ium-1-ide,一种简单的偶氮亚胺,与 3-nitro-2-phenyl-2 的 [3+2] 环加成反应的分子电子密度理论研究H -chromene 在 B3LYP/6-311G(d,p) 计算水平上进行,以揭示实验观察到的立体选择性的起源。电子局域化函数和自然布居分析表明偶氮甲亚胺是一种两性离子三原子组分。概念密度泛函理论反应性指数分析表明,偶氮甲亚胺是一种强亲核试剂,而 3-nitro-2-phenyl-2 H-chromene 是一种良好的亲电子试剂,它解释了由高全局电子密度转移值证实的极性过程。Parr 函数指数很好地解释了实验获得的邻位区域选择性。对气相和i -PrOH 溶液中可能的反应途径的能量分布的分析表明反应具有高外向立体选择性和完全邻位区域选择性,与实验结果非常吻合。对过渡态结构的分析表明,偏爱邻位的分子机制非常不同步区域异构反应通道。使用非共价相互作用、分子中原子的量子理论和基于 Hirshfeld 分布的独立梯度模型的分析表明,存在多个氢键和范德瓦尔斯分子间非共价相互作用是有利于邻-外选择性的因素。最有利途径的键合演化理论研究揭示了两阶段一步的分子机制。

更新日期:2023-04-24
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