Hypervalent Iodine(III)‐Mediated Counteranion Controlled Intramolecular Annulation of Exocyclic β‐Enaminone to Carbazolone and Imidazo[1,2‐<i>a</i>]pyridine Synthesis
作者:Dhananjay Bhattacherjee、Shankar Ram、Arvind Singh Chauhan、Yamini、Sheetal、Pralay Das
DOI:10.1002/chem.201806299
日期:2019.4.23
A highly efficient and flexible protocol for intramolecular annulation of exocyclic β‐enaminones has been disclosed for the synthesis of carbazolones and imidazo[1,2‐a]pyridines through a counter‐anion‐controlled free‐radical mechanism promoted by hypervalent iodine(III). The cooperative behavior of HTIB and AgSbF6 plays a crucial role in the intramolecular annulation process through C−C and C−N bond
为环外β-烯胺酮的分子内环化一个高效和灵活的协议已经公开了carbazolones和咪唑并[1,2的合成一个]吡啶通过高价碘促进的抗衡阴离子控制自由基机理(III) 。HTIB和AgSbF 6的协同行为在通过CC和CN键形成所需的分子内环化过程中起着至关重要的作用。机械学的见解表明,系统中涉及的两个竞争性反应是由抗衡阴离子的性质决定的,抗衡阴离子的性质决定了最终产物的形成。制备并分离了各种咔唑酮和咪唑并[1,2- a ]吡啶分子,收率良好至极佳。