Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520 , United States.
Org Lett. 2019 Jun 7;21(11):3886-3890. doi: 10.1021/acs.orglett.9b00779. Epub 2019 Mar 21.
Imines formed in situ from 2-aminopyridines and aldehydes undergo Rh(III)-catalyzed imidoyl C-H activation and coupling with diazo esters to give pyrido[1,2- a]pyrimidin-4-ones. Aromatic and enolizable aliphatic aldehydes were both effective substrates, and a broad range of functional groups were incorporated at different sites on the heterocyclic products. In addition, methoxy and dimethylamino functionalities could be directly installed on the pyrimidine ring by employing trimethyl orthoformate or N, N-dimethylformamide dimethyl acetal in place of the aldehyde, respectively.
由 2-氨基吡啶和醛原位形成的亚胺经历 Rh(III)催化的酰亚胺 C-H 活化以及与重氮酯的偶联,生成吡啶并[1,2-a]嘧啶-4-酮。芳基和烯醇化的脂肪醛都是有效的底物,在杂环产物的不同位置上都可以引入广泛的官能团。此外,通过分别用原甲酸三甲酯或 N,N-二甲基甲酰胺二甲缩醛代替醛,可将甲氧基和二甲氨基官能团直接安装在嘧啶环上。