Construction of Azaisoflavone Derivatives by Hypervalent Iodine Reagent-Mediated Oxidative Rearrangement of 2’-Nitrochalcone
摘要:
Fabrication of a synthetic azaisoflavone skeleton from 2'-nitrochalcone was done using oxidative rearrangement with a hypervalent iodine reagent. A key intermediate compound, aminoacetal, was prepared from readily available 2'-nitrochalcone via a PhI(OH)OTs-mediated rearrangement, followed by reduction of the nitro group. A variety of azaisoflavones were obtained in moderate to high yields by treatment of the intermediate compound under acidic conditions.