Beilstein Journal of Organic Chemistry | |
AgNTf2-catalyzed formal [3 + 2] cycloaddition of ynamides with unprotected isoxazol-5-amines: efficient access to functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives | |
Xin Meng1  Li Liu1  Laijin Tian1  Xuejun Sun1  Ziping Cao1  Jiekun Zhu1  Yuanling Pang1  | |
[1] Qufu Normal University, School of Chemistry and Chemical Engineering, Qufu 273165, P. R. China; | |
关键词: [3 + 2] cycloaddition; isoxazole; pyrrole; silver catalysis; ynamide; | |
DOI : 10.3762/bjoc.15.255 | |
来源: DOAJ |
【 摘 要 】
A formal [3 + 2] cycloaddition between ynamides and unprotected isoxazol-5-amines has been developed in the presence of catalytic AgNTf2 in an open flask. By the protocol, a variety of functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives can be obtained in up to 99% yield. The reaction mechanism might involve the generation of an unusual α-imino silver carbene intermediate (or a silver-stabilized carbocation) and subsequent cyclization/isomerization to build the significant pyrrole-3-carboxamide motif. The reaction features the use of an inexpensive catalyst, simple reaction conditions, simple work-up without column chromatographic purification for most of products and high yields.
【 授权许可】
Unknown