Rh-Catalyzed [4 + 2] Annulation with a Removable Monodentate Structure toward Iminopyranes and Pyranones by C–H Annulation
作者:Leiqing Fu、Wenqiang Xu、Maoping Pu、Yun-Dong Wu、Yunyun Liu、Jie-Ping Wan
DOI:10.1021/acs.orglett.2c00912
日期:2022.4.29
The Rh-catalyzed reactions of N-pyridinyl enaminones with internal alkynes leading to the synthesis of iminopyranes via a keyC–Hbondactivation and subsequent tautomeric O–H bond cleavage are reported. Moreover, the pyridine ring in the amino group acts as an auxiliary monodentate site for this annulation and can be easily removed by a simple hydrolysis to afford pyranones.
The intramolecular C–N bond forming cross coupling reactions on the enaminones has been achieved for the synthesis of imidazole[1,2-a]pyridines via copper-catalyzed C(sp2)–H amination. This protocol provides a new route for the synthesis of 2-unsubstituted imidazole[1,2-a]pyridines via easily available starting materials.
通过铜催化的C(sp 2)-H氨基化合成咪唑[1,2- a ]吡啶,已经实现了在烯胺上形成分子内C–N键的交叉偶联反应。该方案为通过容易获得的起始原料合成2-未取代的咪唑[1,2- a ]吡啶提供了一条新途径。
Fe-Catalyzed enaminone synthesis from ketones and amines
We have developed an iron-catalyzed direct olefination for enaminone synthesis, with saturated ketones as a source of olefins. This direct ketone β-functionalization reaction has readily available starting materials and a wide range of substrates and requires mild reaction conditions.