2-硅萘与乙炔和苯乙炔杂Diels-Alder反应的理论研究

Theoretical Studies on the Hetero-Diels-Alder Reactions of 2-Silanaphthalenes with Acetylene and Phe

  • 摘要: 采用密度泛函理论(DFT)方法在B3LYP/6-311G(d,p)水平上研究了2-硅萘与乙炔和苯乙炔的杂Diels-Alder反应的微观机理和势能剖面,考察了反应的取代基效应和溶剂效应,并与硅苯参与的类似反应进行了比较.计算结果表明,所研究反应均以协同非同步的方式进行.乙炔分子中碳原子上的苯基取代基对反应活化能垒的影响与产物中苯基所处的位置有关.2-硅萘分子中硅原子上的C(CH3)3或NH2取代基对反应势能剖面的影响一般都比较小,而其上的CCl3取代基对反应势能剖面的影响则比较复杂.苯溶剂对所研究反应的势能剖面影响不大.2-硅萘参与的杂Diels-Alder反应在热力学和动力学上均不如涉及硅苯的相应反应容易进行.

     

    Abstract: Density functional theory (DFT) calculation,at the B3LYP/6-311G(d,p) level of theory,were performed to investigate the mechanism,potential energy surface,substituent effect and solvent effect of hetero-Diels-Alder reactions of 2-silanaphthalenes with acetylene and phenylacetylene and the title reactions were compared with those involving silabenzenes.The results show that all of studied reactions proceed in a concerted but nonsynchronous way.The influences of phenyl at C atom of acetylene on activation barrier of reaction were determined by relative position of phenyl with respect to Si atom in products.The influences of C(CH3)3 or NH2 groups at Si atom of 2-silanaphthalene on the potential energy surface are trivial,however,the influence of CCl3 group is complex.Benzene as a solvent has only trivial influence on the potential energy surface of the studied reactions.The hetero-Diels-Alder reactions of 2-silanaphthalenes with acetylene and phenylacetylene take place more difficultly tha...更多

     

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