Copper-Mediated C4-Benzylations of 5-Aminopyrazoles with 3-Indoleacetic Acids

• DOI: 10.1021/acs.joc.2c02972
• Publication Date: 2023-05-11T12:43:35Z
• Authors: Qiwen Gao; Jinhong Tian; Kangmei Wen; Chen Chen; Xingang Yao; Jianxin Pang; Xiaodong Tang

Herein, we present a copper-mediated C4-benzylation of 5-aminopyrazoles with 3-indoleacetic acids. Various benzylated are prepared in good-to-excellent yields under basic and ligand-free conditions the presence copper acetate. Moreover, this benzylation method is applicable to other substrates, including naphthylamine, 2-aminochromen-4-one, enamines. Some products exhibit antiproliferative activities against cancer cell lines. In addition, C4-benzylated cyclized into 1H-pyrazolo[4',3':6,7]azepino[3,4-b]indoles aldehydes via one-pot two-step processes; notably, fluorescence emissions large Stokes shifts.