Dihydropyridine-fused and pyridine-fused coumarins: Reduction on a glassy carbon electrode in dimethylformamide
作者:Luis J. Nuñez-Vergara、V. Pardo-Jiménez、C. Barrientos、C.A. Olea-Azar、P.A. Navarrete-Encina、J.A. Squella
DOI:10.1016/j.electacta.2012.08.088
日期:2012.12
pyridine-fused coumarins were synthesised and electrochemically characterised in aprotic medium. In both series, the most easily reducible groups were the endocyclic carbonyl groups. The electrochemical mechanism for both types of compounds is strongly dependent on the experimental time-scale. Cyclic voltammetric (CV) reduction on a glassy carbon electrode (GCE) of the endocyclic carbonyl group of d
在这项研究中,合成了两个系列的二氢吡啶-融合和吡啶-融合的香豆素,并在非质子介质中进行了电化学表征。在这两个系列中,最易还原的基团是环内羰基。两种类型化合物的电化学机理都在很大程度上取决于实验时间尺度。二氢吡啶基融合的香豆素内环羰基的玻碳电极(GCE)上的循环伏安(CV)还原涉及具有两个电子转移步骤的ECEC机制,该步骤与化学反应相结合以生成相应的半缩醛衍生物。就吡啶融合的香豆素而言,内环羰基的CV还原涉及EEC机制。ESR研究表明,仅对吡啶融合的衍生物存在稳定的中间体。我们的理论研究表明,自由基物种的自旋密度图主要在香豆素环内离域,表明环内羰基的还原。在二氢吡啶稠合衍生物的情况下,二氢吡啶环的弱酸性氢通过父子型反应使自由基失稳。