Behaviour ofN-Pyridylbenzamides versus Benzanilides in theortho-Directed Lithiation of Masked Aromatic Carboxylic Acids
作者:Andrzej Jóźwiak、Jacek Z. Brzeziński、Mieczysław W. Płotka、Aleksandra K. Szcześniak、Zbigniew Malinowski、Jan Epsztajn
DOI:10.1002/ejoc.200400156
日期:2004.8
examined. The perfect selectivity that has been observed until now in the lithiation of anilides, a reaction used for ortho-functionalisation of masked aromatic carboxylic acids, has been broken; our results indicate that the pyridine ring at the position ortho to the directed metallation group is more susceptible to lithiation than the homoaromatic ring itself. This was proved in an intermolecular comparative
研究了 N-吡啶基苯甲酰胺 1-3 与正丁基锂或仲丁基锂的反应。迄今为止,在苯胺锂化(一种用于掩蔽芳香羧酸的邻位官能化的反应)中观察到的完美选择性已被打破;我们的结果表明,在定向金属化基团邻位的吡啶环比同芳环本身更容易被锂化。这在对苯甲酸、吡啶甲酸苯胺和异烟酰苯胺 14-16 和 N-枯基苯甲酰胺 (17) 的分子间比较研究中得到证实。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)