Liu Dong, Tang Shan, Yi Hong, Liu Chao, Qi Xiaotian, Lan Yu, Lei Aiwen
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (P. R. China).
Chemistry. 2014 Nov 17;20(47):15605-10. doi: 10.1002/chem.201404607. Epub 2014 Oct 3.
Among various types of radical reactions, the addition of carbon radicals to unsaturated bonds is a powerful tool for constructing new chemical bonds, in which the typical applied unsaturated substrates include alkenes, alkynes and imines. Carbonyl is perhaps the most common unsaturated group in nature. This work demonstrates a novel C-O bond formation through carbon-centered radical addition to the carbonyl oxygen of amide or ester, in which amide and ester groups are easily activated through the radical process. EPR spectroscopy and radical clock experiments support the radical process for this transformation, and density functional theory (DFT) calculations support the possibility of carbon-centered radical addition to the carbonyl oxygen of amides or esters.
在各类自由基反应中，碳自由基与不饱和键的加成是构建新化学键的有力手段，其中典型的应用不饱和底物包括烯烃、炔烃和亚胺。羰基或许是自然界中最常见的不饱和基团。这项工作展示了一种通过以碳为中心的自由基加成到酰胺或酯的羰基氧上形成新型C-O键的方法，其中酰胺和酯基可通过自由基过程轻松活化。电子顺磁共振光谱和自由基钟实验支持了这种转化的自由基过程，密度泛函理论（DFT）计算支持了以碳为中心的自由基加成到酰胺或酯的羰基氧上的可能性。
