Nucleophilic Addition to Electron-Rich Heteroaromatics: Dearomatizing Anionic Cyclizations of Pyrrolecarboxamides
摘要:
Despite its electron-rich nature, a pyrrole ring is susceptible to intramolecular nucleophilic attack by organolithiums. The resulting dearomatizing anionic cyclization yields new 5- or 7-membered heterocyclic rings. Formation of a new 5-membered ring, by cyclization of an N-benzylpyrrolecarboxamide, is accompanied by ring opening of the original pyrrole to yield 3-aminovinylpyrrolinones. Formation of a new 7-membered ring, by cyclization of an N-allyl pyrrolecarboxamide, yields bicyclic pyrroloazepinones.
Palladium-Catalyzed Cross-Coupling Reactions of Electron-Deficient Alkenes with<i>N</i>-Tosylhydrazones: Functional-Group-Controlled CC Bond Construction
作者:Huanfeng Jiang、Wei Fu、Huoji Chen
DOI:10.1002/chem.201202051
日期:2012.9.17
palladium‐catalyzed cross‐coupling reaction of electron‐deficient alkenes with N‐tosylhydrazones, which affords diverse CC bonds resulting from the functional‐group‐controlled effect, is reported (see scheme). These cascade transformations present remarkable stereoselectivity and a high synthetic potential. The presence of water substantially promotes both reaction routes.