The ruthenium tetroxide-mediated oxidation of cyclopentane, tetrahydrofuran, tetrahydrothiophene and N-substituted pyrrolidines has been studied computationally by DFT and topological (analysis of the electron localization function, ELF) methods. In agreement with experimental observations and previous DFT calculations, the rate-limiting step of the reaction takes place through a highly asynchronous (3 + 2) concerted cycloaddition through a single transition structure (one kinetic step). The ELF analysis identifies the reaction as a typical one-step-two-stages process and corroborates the existence of a transient carbocation. In the case of pyrrolidines, the carbocation is completely stabilized as an energy minimum in the form of an iminium ion and the reaction takes place in two steps.

中文翻译：

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四氯化钌氧化饱和环中的瞬态和中间碳正离子

四氧化钌介导的环戊烷，四氢呋喃，四氢噻吩和N-取代的吡咯烷的氧化反应已通过DFT和拓扑（电子定位功能分析，ELF）方法进行了计算研究。与实验观察和先前的DFT计算相一致，反应的限速步骤是通过一个单一的过渡结构（一个动力学步骤）通过高度异步的（3 + 2）协同环加成反应进行的。ELF分析将反应识别为典型的一步两阶段过程，并证实了瞬态碳正离子的存在。在吡咯烷的情况下，碳正离子作为亚胺离子形式的最小能量完全稳定，并且反应分两步进行。