Using atmospheric O2 as the stoichiometric oxidant, Pd2+/Cu2+-catalyzed oxidative cyclization of the corresponding bisindolylmaleimides provides the rebeccamycin aglycone and related indolo[2,3-a]pyrrolo[3,4-c]carbazoles in 58–88% yield. The method is operationally simple and utilizes readily prepared substrates, making the process amenable to scaleup.
利用大气Ò 2作为
化学计量的氧化剂,
钯2+ / Cu的2+催化的氧化相应bisindolylmaleimides的环化提供了利拜卡霉素糖苷配基和相关的
吲哚并[2,3-一个]
吡咯并[3,4- c ^ ]在58-
咔唑产率88%。该方法操作简单,并且利用容易制备的基材,使得该方法适合规模化生产。