二氯乙烯锗烯与甲硫醛环加成的反应机理(英文)

Cycloaddition Reaction Mechanism between Dichloromethylene Germylene and Methanethial

利用MP2/6-311+G*方法计算了单线态二氯乙烯锗烯与甲硫醛的各种反应机理.计算结果表明两者之间的环加成反应具有很好的选择性,优势反应路径分为三步:首先两种反应物经过无能垒的放热反应形成中间体INT,然后INT经历过渡态TS3异构化为P31,最后P31继续与甲硫醛反应形成二环杂环化合物P33.其中第一步反应放热103.4kJ·mol-1,后两步反应能垒分别为0.7和32.3kJ·mol-1.

Theoretical calculations at MP2/6-311＋G^＊ level were employed to investigate various reaction mechanisms between singlet dichloromethylene germylene and methanethial. Calculation results indicate that the dominant reaction pathway for this reaction consists of three steps. The two reactants initially form an intermediate INT through a barrierfree exothermic reaction of 103.4 kJ·mol^-1. This intermediate then isomerizes to P31 via a transition state TS3 with an energy barrier of 0.7 kJ·mol^-1. P31 finally reacts with methanethial to form the germanic heteropolycyclic product P33 with an energy barrier of 32.3 kJ·mol^-1. This cycloaddition reaction thus has excellent selectivity.