Metal-free synthesis of benzimidazo[1,2-c]quinazolin-6-ones with indole and benzenediamine oxidized by I2/TBHP
作者:Zhen Dai、Songhua Li、Yunyi Li、Lei Feng、Chen Ma
DOI:10.1016/j.tet.2019.02.022
日期:2019.3
A variety of benzimidazo[1,2-c]quinazolin-6-ones derivatives can be accessed in moderate to good yields under simple and metal-free reaction conditions using indoles and o-benzenediamines oxidized by iodine and TBHP. This procedure works in reasonable yields for different indoles as well as o-benzenediamines thus may provide a good synthesis of quinazolinones. A TBHP oxidized ring expansion reaction
sustainable approach to access amidinyl radical intermediates through the anodic cleavage of N−H bonds. The resulting nitrogen‐centered radicals undergo cyclizations with (hetero)arenes, followed by rearomatization, to afford functionalized tetracyclic benzimidazoles in a highly straightforward and efficient manner. This metal‐ and reagent‐free C−H/N−H cross‐coupling reaction exhibits a broad substrate