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.

中文翻译：

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AgNTf2催化的未保护的异恶唑-5-胺类酰胺的正式[3 + 2]环加成反应：有效获得官能化的5-氨基-1H-吡咯-3-羧酰胺衍生物

在开放式烧瓶中，在催化的AgNTf ₂存在下，开发了酰胺和未保护的异恶唑-5-胺之间的正式[3 + 2]环加成反应。通过该协议，可以以高达99％的收率获得各种功能化的5-氨基-1 H-吡咯-3-羧酰胺衍生物。反应机理可能涉及生成异常的α-亚氨基亚银卡宾中间体（或银稳定的碳正离子）和随后的环化/异构化，以构建显着的吡咯-3-羧酰胺基序。该反应的特点是使用便宜的催化剂，简单的反应条件，无需柱色谱纯化即可进行简单后处理的大多数产品，并且收率很高。