6-芳酰基菲啶合成反应的机理及取代基电子效应研究  

Mechanism and electronic effect for the synthesis of 6-aroylated phenanthridines: a theoretical study

作　　者：徐婷[1] 戚孝天[1] 蓝宇[1] 

机构地区：[1]重庆大学化学化工学院,重庆400030

出　　处：《中国科学：化学》2016年第6期616-622,共7页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(编号:21372266;51302327);重庆大学"青年百人计划"(编号:0903005203191);中央高校(重庆大学)基础研究经费(编号:106112015CDJZR228806)资助项目

摘　　要：本文运用密度泛函理论(DFT)计算,系统研究了碱促均裂芳香取代合成6-酰基菲啶的反应机理.计算结果表明,叔丁氧自由基和苯甲醛间的自由基传递反应是整个反应的决速步骤.随后酰基自由基对氰基的亲核进攻以及自由基环化过程是快速步骤.此外,我们还利用Hammett曲线研究了反应过程中不同位置上取代基的电子效应.研究结果表明,氰基对位上被吸电子基团取代时有利于酰基自由基的亲核进攻,酰基对位被给电子基团取代时有助于自由基环化过程的发生.Density functional theory（DFT） calculations were employed to study the mechanism for the synthesis of 6-aroylated phenanthridines via base promoted homolytic aromatic substitution. Computational results suggest that the radical transfer process between butyloxycarbonyl radical and benzaldehyde is the rate-determining step. Subsequent nucleophilic addition of acyl radical towards cyano group and the radical cyclization step are facile process. Besides, the electronic effect of substituents on different sites was also investigated using the Hammett plot. The obtained results indicate that, the electron-withdrawing group on para-position of cyano group would facilitates the nucleophilic addition of acyl radical, and the electron-donating group on para-position of acyl group would promote the radical cyclization step.

关 键 词：菲啶 密度泛函理论计算 自由基反应 Hammett曲线 取代基电子效应 

分 类 号：O621.25[理学—有机化学]