Beccalli Egle M, Broggini Gianluigi, Clerici Francesca, Galli Simona, Kammerer Claire, Rigamonti Micol, Sottocornola Silvia
Istituto di Chimica Organica "A. Marchesini", Facolta di Farmacia, Universita di Milano, via Venezian 21, 20133 Milano, Italy.
Org Lett. 2009 Apr 2;11(7):1563-6. doi: 10.1021/ol900171g.
Allenamides of alpha-amino acids were converted into enantiopure 2-vinylimidazolidin-4-ones by a carbopalladation/exo-cyclization process. The products were obtained in 2.5:1-5.5:1 dr, with 94-99% ee. The palladium-catalyzed carbonylative cyclization of the same substrates afforded enone structures. Starting from properly substituted allenamides, an intramolecular carbopalladation followed by intramolecular amination gave rise to tricyclic fused-ring imidazolidinones.
α-氨基酸的烯丙酰胺通过碳钯化/外环化过程转化为对映体纯的2-乙烯基咪唑烷-4-酮。产物的非对映体比例为2.5:1至5.5:1，对映体过量为94%-99%。相同底物的钯催化羰基化环化反应得到烯酮结构。从适当取代的烯丙酰胺开始，分子内碳钯化后接着分子内胺化反应生成三环稠合环咪唑烷酮。
