Rhodium-Catalyzed Direct Annulation of Aldehydes with Alkynes Leading to Indenones: Proceeding through in Situ Directing Group Formation and Removal
摘要:
The Rh-catalyzed direct annulation of an aldehyde with an alkyne leading to indenone was achieved. The in situ temporal installation of acetylhydrazine enables the annulation of the ortho arene C-H bond with alkynes to form ketone hydrazone. Subsequently, the in situ directing group removal takes place since ketone hydrazone is more susceptible toward hydrolysis than aldehyde hydrazone. Notably, this procedure tolerates a series of functional groups, such as methoxyl, acetylamino, fluoro, trifluoromethyl, methoxycarbonyl, chloro, and bromo groups.
Rhodium/Copper-Catalyzed Annulation of Benzimides with Internal Alkynes: Indenone Synthesis through Sequential CH and CN Cleavage
作者:Bi-Jie Li、Hao-Yuan Wang、Qi-Lei Zhu、Zhang-Jie Shi
DOI:10.1002/anie.201200271
日期:2012.4.16
Doubled up: A rhodium(III)/copper(II) system co‐catalyzes the annulation of benzimides with internal alkynes for the synthesis of indenones (see scheme; Cp*=C5Me5). The reaction involves an uncommon nucleophilic addition of a transition‐metal–carbon bond to an imide moiety. This novel reaction provides a facile route to synthesize indenones from readily available benzimides and internal alkynes.
加倍:铑(III)/铜(II)系统共催化苯并酰亚胺与内部炔烃的环化反应,以合成茚满(参见方案; Cp * = C 5 Me 5)。该反应涉及到过渡金属-碳键向酰亚胺部分的不常见亲核加成。该新颖的反应提供了从容易获得的苯甲酰亚胺和内部炔烃合成茚满的简便途径。