DataSheet1_Annulation of O-silyl N,O-ketene acetals with alkynes for the synthesis of dihydropyridinones and its application in concise total synthesis of phenanthroindolizidine alkaloids.pdf

The formation of N-heterocycles with multiple substituents is important in organic synthesis. Herein, we report a novel method for the construction of functionalized dihydropyridinone rings through the annulation of an amide α-carbon with a tethered alkyne moiety. The reaction of the amide with the alkyne was achieved via O-silyl N,O-ketene acetal formation and silver-mediated addition. Furthermore, the developed method was applied for the total synthesis of phenanthroindolizidine and phenanthroquinolizidine alkaloids. By varying the coupling partners, a concise and collective total synthesis of these alkaloids was achieved.

多取代氮杂环（N-heterocycles）的构建在有机合成领域具有重要价值。本文报道了一种通过酰胺α-碳与系链炔基单元的环化反应，构建官能化二氢吡啶酮环的新型方法。该酰胺与炔基的反应经由O-硅基N,O-烯酮缩醛的生成及银介导的加成反应得以实现。此外，所开发的方法被应用于菲并吲哚里西啶（phenanthroindolizidine）与菲并喹喏里西啶（phenanthroquinolizidine）类生物碱的全合成。通过改变偶联底物，即可实现该类生物碱的简洁且集合式全合成。