AuCl3催化炔酮分子内环化反应的机理

采用密度泛函理论的B3LYP方法研究炔酮发生分子内环化生成菲衍生物的反应机理.结果表明：在无催化剂和AuCl₃催化剂作用下，反应均可通过2+2]和6+2]途径生成产物.无催化剂时，两条途径控制步骤的能垒都较高，但是2+2]途径的能垒比6+2]途径的低32.01 kJ·mol^-1，故反应主要通过2+2]途径进行.在AuCl₃催化作用下，反应的优势途径为2+2]途径，其能垒为137.05 kJ·mol^-1.比较活化能发现，AuCl₃催化剂明显地降低了反应能垒，使反应能够顺利进行.

Mechanism of Acetylenic-Keton Intramolecular Cyclization Reaction Catalyzed by AuCl3

Density functional theory with B3LYP functionals was used to study generating phenanthrene derivatives mechanism of acetylenic-keton intramolecular cyclization reaction catalyzed by AuCl₃. It shows that the reaction can occur through 2+2] and 2+6] reaction pathways with and without AuCl₃ catalyst. Without catalyst, energy barrier of rate determining step of 2+2] pathway is lower than that of 2+6] pathway by 32.01 kJ·mol^-1. Reaction mainly occurs through 2+2] pathway. With AuCl₃ catalyst, dominent reaction pathway is still 2+2] pathway with an energy barrier of rate determining step of 137.05 kJ·mol^-1. Energy barrier of rate determining step of four-membered ring pathway with AuCl₃ catalyst is 102.72 kJ·mol^-1 lower than that of reaction without catalyst. This difference indicates that AuCl₃ is an efficient catalyst which can raise reaction rate and moderate reaction condition.