AgNTf2-catalyzed formal [3 + 2] cycloaddition of ynamides with unprotected isoxazol-5-amines: efficient access to functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives

Beilstein Journal of Organic Chemistry

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