Enol Radical Cations in Solution. 13. First Example of a Radical Dication Rearrangement. One-Electron Oxidation of Dihydrobenzofuranyl Cations Leads to Drastic Rate Enhancement in the Oxidative Benzofuran Formation from Enols
作者:Michael Schmittel、Anja Langels
DOI:10.1021/jo980859n
日期:1998.10.1
the alpha-position. Oxidative benzofuran formation from these enols is unusually slow because a key intermediate in the reaction, the dihydrobenzofuranyl cation X(+), is substantially stabilized vs rearrangement by the attached electron-releasing substituents. The persistent cations X(+) were characterized by (1)H NMR and cyclic voltammetry, and the kinetics of their rearrangement was followed by UV/vis
报道了六个稳定,简单的烯醇E1-E6的合成和电化学研究,这些烯醇E1-E6的特征是在α位上具有释放电子的取代基。由这些烯醇形成的氧化苯并呋喃异常缓慢,这是因为反应中的关键中间体,二氢苯并呋喃基阳离子X(+),相对于重排是通过附着的释放电子的取代基来稳定的。持久性阳离子X(+)的特征在于(1)H NMR和循环伏安法,其重排动力学随后是UV / vis。值得注意的是,在X(+)的单电子氧化为自由基指示后,苯并呋喃B的形成显着加速了> 10(6)。