Cu-Catalyzed one-pot synthesis of thiochromeno-quinolinone and thiochromeno-thioflavone <i>via</i> oxidative double hetero Michael addition using <i>in situ</i> generated nucleophiles
作者:Nallappan Sundaravelu、Govindasamy Sekar
DOI:10.1039/d0cc03210g
日期:——
catalyzed three-component synthesis of π-conjugated tetracyclic thiochromeno-quinolinone and thiochromeno-thioflavone was established via oxidative double hetero Michael additionusing in situ generated nucleophiles. Xanthate plays a dual role as an odourless sulfur source and a chemoselective reducing agent. The in situ formed iodine plays a crucial role in the oxidation step.
unexpected [5 + 1 + 3] cascade cyclization to the preparation of benzo[4,5]thieno[3,2-d]pyrimidine derivatives has been disclosed. In the new protocol, o-nitrochalcones reacted with elemental sulfur and guanidine promoted by NaOH, which reacted in EtOH for 20 min, providing structurally diverse benzo[4,5]thieno[3,2-d]pyrimidines with good yields (77–89%) and wide substrate compatibility (33 examples)
已经公开了用于制备苯并[4,5]噻吩并[3,2- d ]嘧啶衍生物的意想不到的[5+1+3]级联环化。在新方案中,邻硝基查尔酮与 NaOH 促进的元素硫和胍反应,在 EtOH 中反应 20 分钟,提供结构多样的苯并[4,5]噻吩并[3,2- d ]嘧啶,收率良好(77- 89%)和广泛的基材兼容性(33 个示例)。