TY - JOUR A1 - Cao, Ziping A1 - Zhu, Jiekun A1 - Liu, Li A1 - Pang, Yuanling A1 - Tian, Laijin A1 - Sun, Xuejun A1 - Meng, Xin T1 - AgNTf2-catalyzed formal [3 + 2] cycloaddition of ynamides with unprotected isoxazol-5-amines: efficient access to functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives JF - Beilstein Journal of Organic Chemistry PY - 2019/// VL - 15 SP - 2623 EP - 2630 SN - 1860-5397 DO - 10.3762/bjoc.15.255 PB - Beilstein-Institut JA - Beilstein J. Org. Chem. UR - https://doi.org/10.3762/bjoc.15.255 KW - [3 + 2] cycloaddition KW - isoxazole KW - pyrrole KW - silver catalysis KW - ynamide N2 - 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. ER -