A cascade AgOTf-catalyzed chemoselective approach to 3,5/1,3-disubstitued pyrazoles from propargylic alcohols and para-tolylsulfonohydrazide has been developed. Good chemoselectivity is observed depending on the different substituents in the alkyne moiety of the propargylic alcohols, generating two different kinds of products through different aromatization mechanisms. The pyrazolo[5,1-a]isoquinoline skeleton can also be effectively constructed by this method through a cascade bicyclization process.
开发了一种瀑布式AgOTf催化的
化学选择性方法,能够从
丙炔醇和对
甲苯磺酰
肼得到3,5/1,3二取代的
吡唑。根据
丙炔醇中
炔烃部分的不同取代基,观察到良好的
化学选择性,通过不同的芳构化机制生成两种不同类型的产物。该方法还可以通过级联双环化过程有效构建
吡唑[5,1-a]
异喹啉骨架。