Synthetic and DFT Studies Towards a Unified Approach to Phlegmarine Alkaloids: Aza-Michael Intramolecular Processes Leading to 5-Oxodecahydroquinolines
作者:Ben Bradshaw、Carlos Luque-Corredera、Gisela Saborit、Carlos Cativiela、Ruth Dorel、Carles Bo、Josep Bonjoch
DOI:10.1002/chem.201301715
日期:2013.10.4
facilitated through the use of DFT‐based mechanistic studies, which enabled the observed diastereodivergent course of the azacyclization to be rationalized. The varying stereochemistry and stability of the resulting decahydroquinolines was found to depend on whether a β‐keto ester or ketone were embedded in the substrates undergoing aminocyclization. This synthetic approach gave access not only to both diastereomeric
描述了一种非对映选择性的顺式-5-氧代十二氢喹啉合成方法,其中在一个反应罐中生成了三个立体中心。该反应涉及由非手性无环甲苯磺胺系β-酮酯促成的氢氧化锂促进的罗宾逊环化/分子内氮杂-迈克尔多米诺过程。通过使用基于DFT的机理研究,促进了该反应的发展和范围,使合理的非对映异构化过程得以观察到。发现所得十氢喹啉的立体化学和稳定性的变化取决于是否将β-酮酸酯或酮嵌入进行氨基环化的底物中。这种合成方法不仅可以同时获得两个非对映异构体的顺式通过相应的N未取代的顺式-5-氧代十二氢喹啉的差向异构化过程,可从相同的前体得到十氢喹啉,也可将其转变为相应的反式异构体。所描述的方法提供了高级构建基块,其中包含了完全合成Phlegmarine生物碱所需的三个相对立体化学。