An efficient TBHP/TBAI-mediated protocol for the synthesis of 4H-chromen-4-ones from chroman-4-ones via oxidative C–C bond formation
作者:Habtamu Abebe Agisho、Suboot Hairat、Mehvash Zaki
DOI:10.1007/s00706-020-02576-8
日期:2020.4
AbstractA transition metal-free and efficient TBHP/TBAI-mediated protocol has been developed for the synthesis of 4H-chromen-4-ones from chroman-4-ones via oxidative C–C bond formation. It proceeds in the presence of a catalytic amount of tetrabutylammonium iodide and oxidant tert-butyl hydroperoxide (TBHP, 5–6 M in decane) to afford the corresponding products in good to excellent yields. Furthermore
摘要已经开发了一种无过渡金属且高效的TBHP / TBAI介导的方案,用于通过氧化C-C键形成从苯并吡喃-4-酮合成4 H -chromen-4-酮。它在催化量的碘化四丁基铵和氧化剂叔丁基过氧化氢(TBHP,癸烷中的5-6 M)存在下进行,以良好的收率获得了相应的产物。此外,已经观察到TBHP的浓度增加到30mol%大大增加了4 H的收率。-chromen-4-ones,进一步增加将导致产率降低。该反应的机理涉及最初生成叔丁氧基自由基,其通过氧化单电子转化被转化为碘代色烷-4-酮。之后,将碘化氢从碘代chroman-4-one中除去,得到所需的产物,即4 H -chromen-4-ones。此外,这是通过脱氢反应由n -Bu 4 NI / TBHP介导的C–C键的罕见例子。 图形摘要