An Approach for the Synthesis of Pyrazolo[1,5-<i>a</i>]pyrimidines via Cu(II)-Catalyzed [3+3] Annulation of Saturated Ketones with Aminopyrazoles
作者:Jian Ren、Shihua Ding、Xiaonian Li、Ran Bi、Qinshi Zhao
DOI:10.1021/acs.joc.1c01343
日期:2021.9.17
A one-step synthesis of diversely substituted pyrazolo[1,5-a]pyrimidines from saturated ketones and 3-aminopyrazoles is presented. This transformation involves the in situ formation of α,β-unsaturated ketones via a radical process, followed by [3+3] annulation with 3-aminopyrazoles in one pot. Mechanistic studies have shown that the dual C(sp3)–H bond functionalization of inactive ketones is required
提出了从饱和酮和 3-氨基吡唑一步合成不同取代的吡唑并[1,5- a ]嘧啶。这种转化涉及通过自由基过程原位形成 α,β-不饱和酮,然后在一个锅中与 3-氨基吡唑进行 [3+3] 环化。机理研究表明,形成标题化合物需要非活性酮的双 C(sp 3 )-H 键官能化。值得注意的是,这种脱氢偶联过程提供了从市售底物获得大量具有抗肿瘤潜力的官能化吡唑并[1,5- a ]嘧啶的途径。