Bobkov Alexander S, Vitkovskaya Nadezhda M, Trofimov Boris A
Laboratory of Quantum Chemical Modeling of Molecular Systems, Irkutsk State University, 1 K. Marx Street, 664003 Irkutsk, Russian Federation.
A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky Street, 664033 Irkutsk, Russian Federation.
J Org Chem. 2020 May 15;85(10):6463-6470. doi: 10.1021/acs.joc.0c00353. Epub 2020 Apr 24.
Pyrrole synthesis from ketoximes and acetylene in the KOH/dimethyl sulfoxide (DMSO) superbase medium (here abbreviated as the KOA reaction) provided access to a wide variety of 2-substituted and 2,3-disubstituted pyrroles from the available starting materials (enolizable ketones and acetylene). All steps of the KOA reaction mechanism are studied, for the first time, in detail at a uniform theoretical level for the cascade assembly of 4,5,6,7-tetrahydroindole from cyclohexanone oxime and acetylene. Our results explain the reasons why some earlier postulated intermediates have not been detected during the reaction. Alternative channels for the formation of intermediates of 3-pyrroles are considered. The qualitative agreement of the obtained results with kinetic studies is demonstrated.
在氢氧化钾/二甲基亚砜（DMSO）超强碱介质中，由酮肟和乙炔合成吡咯（此处简称为KOA反应），能够从现有的起始原料（可烯醇化的酮和乙炔）制得多种2-取代和2,3-二取代的吡咯。首次在统一的理论水平上详细研究了KOA反应机理的所有步骤，该反应是由环己酮肟和乙炔级联组装4,5,6,7-四氢吲哚。我们的结果解释了为什么在反应过程中未检测到一些早期推测的中间体的原因。考虑了形成3-吡咯中间体的替代途径。结果表明，所得结果与动力学研究在定性上是一致的。
