Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, USA.
J Org Chem. 2012 Jul 6;77(13):5788-93. doi: 10.1021/jo300922p. Epub 2012 Jun 21.
Friedel-Crafts acylation has been known since the 1870s, and it is an important organic synthetic reaction leading to aromatic ketone products. Friedel-Crafts acylation is usually performed with carboxylic acid chlorides or anhydrides, while amides are generally not useful substrates in these reactions. Despite being the least reactive carboxylic acid derivative, we have found a series of amides capable of providing aromatic ketones in good yields (55-96%, 17 examples). We propose a mechanism involving diminished C-N resonance through superelectrophilic activation and subsequent cleavage to acyl cations.
弗里德尔-克拉夫茨酰化反应自 19 世纪 70 年代以来就为人所知，它是一种重要的有机合成反应，可得到芳香酮产物。弗里德尔-克拉夫茨酰化反应通常使用羧酸酰氯或酸酐进行，而酰胺通常不是这些反应中的有用底物。尽管酰胺是羧酸衍生物中反应性最低的，但我们已经发现了一系列酰胺能够以良好的收率（55-96%，17 个实例）提供芳香酮。我们提出了一种涉及通过超亲电子活化和随后裂解形成酰基阳离子来减小 C-N 共振的机制。
