通过三烯胺催化仲手性胺研究了醌亚胺缩酮和2,4-二烯醛的不对称Diels-Alder环加成反应。在级联芳构化/分子间半缩醛形成序列(高达98%ee,> 19:1 dr)后,以中等至良好的收率和高至优异的对映选择性有效地构建了一系列手性三环苯并[ de ]喹诺酮衍生物。该方法和有用的产品支架可以在合成和医学领域中进一步使用。
Organocatalytic Chemo- and Regioselective Oxyarylation of Styrenes via a Cascade Reaction: Remote Activation of Hydroxyl Groups
作者:Yu-Chen Zhang、Fei Jiang、Shu-Liang Wang、Feng Shi、Shu-Jiang Tu
DOI:10.1021/jo500859b
日期:2014.7.3
The first organocatalytic oxyarylation of styrenes has been established through a cascade of vinylogous Michael adclition/alkoxyl transfer reactions of o- or p-hydroxylstyrenes with quinone imine ketals. The process leads to a highly chemo- and regioselective oxyarylation of styrenes and provides access to m-alkylated anilines in generally high yields and excellent diastereoselectivity (up to 99% yield, >95:5 dr). An investigation of the reaction pathway revealed that the existence and position of the hydroxyl group of styrene played crucial roles in the cascade reaction, suggesting that the two reactants were simultaneously activated by binaphthyl-derived phosphoric acid via hydrogen bonding interactions and long-distance conjugative effects. In addition, the activating group of the hydroxyl functionality in the products can be easily removed or transformed, demonstrating the applicability and utility of this strategy in styrene oxyarylation and in the synthesis of styrene-based compounds.