Zhang Zheng-Feng, Su Ming-Der
Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan.
Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
Dalton Trans. 2023 Apr 11;52(15):4796-4807. doi: 10.1039/d3dt00313b.
The influence of Group 15 elements (G15s) on the reactivity of the cycloaddition reactions of inorganic 1,3-dipolar analogs with cyclooctyne was computationally explored with density functional theory. To this end, the G15G15G15'-based 1,3-dipole, an interestingly representative model molecule of 1,3-dipole chemistry, was selected. The present computational investigations suggest that all and molecules can be energetically feasible to undergo 1,3-dipolar cycloaddition reactions with cyclic alkynes, except for only the 1,3-dipole molecule. The key factor, which can greatly affect the activation barriers, is quantitatively analyzed in detail through the frontier molecular orbital (FMO) theory, the activation strain model (ASM), and the energy decomposition analysis (EDA) approach. Our theoretical findings based on the FMO theory and the EDA suggest that two types of bonding interactions occur in such 1,3-dipolar cycloaddition reactions: forward bonding (filled p-π orbital (cyclooctyne) → the empty p-π* orbital (G15 = G15)) and back bonding (empty p-π* orbital (cyclooctyne) ← the lone pair (G15')). Notably, the bonding interactions of the former mechanism are much stronger than those of the latter mechanism. Evidence from the ASM reveals that the activation barriers of G15G15G15'-based 1,3-dipolar cycloaddition reactions strongly depend on the atomic radius of the G15 element. These theoretical conclusions allow a number of predictions to be made.
利用密度泛函理论对第15族元素（G15）对无机1,3 - 偶极类似物与环辛炔环加成反应活性的影响进行了计算研究。为此，选择了基于G15G15G15'的1,3 - 偶极，这是1,3 - 偶极化学中一个有趣的代表性模型分子。目前的计算研究表明，除了仅有的 1,3 - 偶极分子外，所有 和 分子与环状炔烃发生1,3 - 偶极环加成反应在能量上都是可行的。通过前沿分子轨道（FMO）理论、活化应变模型（ASM）和能量分解分析（EDA）方法，对能够极大影响活化能垒的关键因素进行了详细的定量分析。我们基于FMO理论和EDA的理论研究结果表明，在这种1,3 - 偶极环加成反应中发生了两种类型的键相互作用：正向键合（填充的p - π轨道（环辛炔）→空的p - π轨道（G15 = G15））和反向键合（空的p - π轨道（环辛炔）←孤对电子（G15'））。值得注意的是，前一种机制的键相互作用比后一种机制的要强得多。ASM的证据表明，基于G15G15G15'的1,3 - 偶极环加成反应的活化能垒强烈依赖于G15元素的原子半径。这些理论结论使得可以做出许多预测。
