Synthesis of Fluorenes<i>via</i>the Palladium-Catalyzed 5-<i>exo-dig</i>Annulation of<i>o</i>-Alkynylbiaryls
作者:Natalia Chernyak、Vladimir Gevorgyan
DOI:10.1002/adsc.200800765
日期:2009.5
The direct Pd-catalyzed intramolecular rapidly with electron-deficient benzene ring, which, in hydroarylation of o-alkynyl biaryls proceeded in highly combination with a substantial isotope effect observed, stereoselective manner producing fluorenes 2, the products of 5-exo-dig cyclization, in excellent yields. The cascade intermolecular arylation, incorporated in this transformation, allowed for efficient
直接 Pd 催化分子内的缺电子苯环迅速发生分子内反应,在邻炔基联芳基的加氢芳基化过程中与观察到的大量同位素效应高度结合,立体选择性方式产生芴2,5-exo-dig 环化的产物,以优异的产量。级联分子间芳基化,纳入该转化,允许有效合成完全取代的芴12。这些环化在缺电子苯环下进行得更快,结合观察到的大量同位素效应,强烈支持CH活化机制为关键的环化步骤。