Eşsiz Selçuk
Department of Chemistry, Faculty of Science, Atatürk University Erzurum 25240 Turkey
Department of Chemical Engineering, Faculty of Engineering, Hakkari University Hakkari 30000 Turkey.
RSC Adv. 2021 May 20;11(30):18246-18251. doi: 10.1039/d1ra01649k. eCollection 2021 May 19.
A computational study of metal-free cyanomethylation and cyclization of aryl alkynoates with acetonitrile is carried out employing density functional theory and high-level coupled-cluster methods, such as coupled-cluster singles and doubles with perturbative triples [CCSD(T)]. Our results indicate that the reaction of aryl alkynoates with acetonitrile in the presence of -butyl peroxybenzoate (TBPB) under metal-free conditions tends to proceed through cyanomethylation, spirocyclization and ester migration of the kinetically favoured coumarin derivatives. 1,2-Ester migration in the spiro-radical intermediate 10 does not proceed the formation of the carboxyl radical 11 suggested by Sun and co-workers. Our results also demonstrate that the -butoxy radical is substantially responsible the formation of the cyanomethyl radical by the abstraction of a hydrogen atom from acetonitrile.
采用密度泛函理论和高水平耦合簇方法，如耦合簇单双激发并微扰包含三激发态的方法[CCSD(T)]，对芳基炔酸酯与乙腈的无金属氰甲基化和环化反应进行了计算研究。我们的结果表明，在无金属条件下，芳基炔酸酯与乙腈在过氧苯甲酸叔丁酯（TBPB）存在下的反应倾向于通过动力学有利的香豆素衍生物的氰甲基化、螺环化和酯迁移进行。螺环自由基中间体10中的1,2-酯迁移并没有像Sun及其同事所提出的那样生成羧基自由基11。我们的结果还表明，叔丁氧基自由基主要负责通过从乙腈中提取氢原子而形成氰甲基自由基。
