Elucidating the origin of selectivity of [3 2]-cycloaddition reactions between thioketone and carbohydrate-derived nitrones by the DFT
Elucidating the origin of selectivity of [3 2]-cycloaddition reactions between thioketone and carbohydrate-derived nitrones by the DFT
复制标题
通过 DFT 阐明硫酮和碳水化合物衍生的硝酮之间的 [3 2]-环加成反应选择性的起源
DOI：
10.1007/s00894-019-4104-6
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发表时间：
2019
影响因子：
2.2
通讯作者：
Xue Ying
中科院分区：
文献类型：
--
作者：
Yang Junxia;Zhang Yan;Yang Yongsheng;Xue Ying
采用密度泛函理论（DFT）方法，在M06-2X/6-311+G（d，p）//M06-2X/6-31+ G（d，p）水平上，结合溶剂化SMD模型，研究了四氢呋喃（THF）中硫酮与糖衍生硝酮的[3 + 2]-环加成（32 CA）反应选择性的机理和起源.计算结果表明，32 CA反应是以异步一步法进行的。对于硫酮的化学选择性，C=S键作为偶极亲电体攻击三原子组分硝酮的反应性比C=O键更优先。理论结果也证实了硫酮与糖衍生硝酮的两个32 CA反应的立体选择性，反式产物比顺式产物更有利，反式/合成产物的预测值与文献中的实验值一致。此外，对概念密度泛函理论反应性指数的分析表明，32 CA反应具有极性特征。弱非共价相互作用和Parr函数分析揭示了立体选择性的来源。硫酮与糖衍生硝酮的[3 + 2]-环加成反应
The mechanism and origin of selectivity for [3 + 2]-cycloaddition (32CA) reactions between thioketone and carbohydrate-derived nitrones in THF were investigated by using the density functional theory (DFT) at the M06-2X/6-311+G(d,p)//M06-2X/6-31+G(d,p) level of theory combined with the solvation SMD model. The calculated results revealed that the 32CA reactions proceed through the asynchronous one-step manner. For the chemoselectivity in thioketone, the C=S bond as a dipolarophile attacking three-atom-component (TAC) nitrone in reactivity was more preferential than the C=O bond. The theoretical results also confirmed the stereoselectivity of two 32CA reactions of thioketone with carbohydrate-derived nitrones with theanti-form product being more favored than thesyn-form product, and the predictedanti/synproduct ratios are in agreement with the experimental ones in literature. Furthermore, the analysis of the conceptual density functional theory reactivity indices showed that the 32CA reactions have polar character. Weak noncovalent interaction and Parr function analyses are used to reveal the origin of the stereoselectivity.Graphical abstract[3 + 2]-cycloaddition reactions between thioketone and carbohydrate-derived nitrones