Construction of Multifunctionalized Azopyrazoles by Silver- Catalyzed Cascade Reaction of Diazo Compounds
作者:Rameshwar Prasad Pandit、Yong Rok Lee
DOI:10.1002/adsc.201500197
日期:2015.8.24
silver trifluoromethanesulfonate (AgOTf)‐catalyzed cascade reaction of α‐diazo‐β‐keto esters with two arylhydrazines or two arylhydrazine hydrochlorides. This cascade reaction included pyrazolone formation, NH insertion, and oxidation. For the synthesis of more diverse azopyrazoles bearing two different aromatic rings, the silver(I)‐catalyzed cascade reaction of 4‐diazopyrazol‐3‐one with arylhydrazine
高效的单锅三氟甲磺酸银(AgOTf)催化α-重氮-β-酮酸酯与两个芳基肼或两个芳基肼盐酸盐的级联反应可以合成高收率的多种多取代偶氮吡唑。该级联反应包括吡唑啉酮的形成,NH 3的插入和氧化。为了合成带有两个不同芳环的更多种类的偶氮并吡唑,还开发了由银(I)催化的4-重氮吡唑-3-酮与芳基肼盐酸盐的级联反应。这些方法的优点是易于处理,温和的反应条件以及有效且无毒的催化剂使用。