Department of Chemistry and Fujian Provincial Key Laboratory of Chemical Biology, Collaborative Innovation Centre of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University , Xiamen, Fujian 361005, P. R. China.
State Key Laboratory of Elemento-Organic Chemistry, Nankai University , Tianjin 300071, P. R. China.
J Org Chem. 2016 Oct 7;81(19):9020-9027. doi: 10.1021/acs.joc.6b01647. Epub 2016 Sep 21.
The direct transformation of common secondary amides into aromatic ketimines and aromatic ketones with C-C bond formation is described. The reaction can also be used for N-deacylation of secondary amides to release amines. This method consists of in situ amide activation with triflic anhydride and intermolecular capture of the resulting highly electrophilic nitrilium intermediate with an arene. The reaction is applicable to various kinds of secondary amides (electrophiles), but only electron-rich and moderately electron-rich arenes can be used as nucleophiles. Thanks to the use of bench stable arenes instead of reactive and basic organometallics as nucleophiles, the reaction proceeded with high chemoselectivity at the secondary amido group in the presence of a series of sensitive functional groups such as aldehyde, ketone, ester, cyano, nitro, and tertiary amido groups. The reaction can be viewed as a Friedel-Crafts-type reaction using secondary amides as acylating agents or as an intermolecular version of the Bischler-Napieralski reaction.
本文描述了一种将常见仲酰胺直接转化为含 C-C 键的芳基酮亚胺和芳基酮的方法。该反应也可用于仲酰胺的 N-脱酰基化以释放胺。该方法包括用三氟甲磺酸酐原位激活酰胺，然后用芳环捕获生成的高亲电性亚硝鎓中间体。该反应适用于各种仲酰胺（亲电试剂），但只能用富电子和中等富电子的芳环作为亲核试剂。由于使用了稳定的芳环代替反应性和碱性有机金属作为亲核试剂，因此在一系列敏感官能团如醛、酮、酯、氰基、硝基和叔酰胺基存在下，反应可以在仲酰胺基上具有高化学选择性地进行。该反应可以看作是使用仲酰胺作为酰化剂的 Friedel-Crafts 型反应，或者是 Bischler-Napieralski 反应的分子间版本。
