Improved Synthesis of Symmetrical 2,5-Diarylimidazoles by One-Pot Palladium-Catalyzed Direct Arylation Tailored on the Electronic Features of the Aryl Halide
作者:Marco Lessi、Gianmarco Panzetta、Giulia Marianetti、Fabio Bellina
DOI:10.1055/s-0036-1589071
日期:2017.10
Two methods for the one-pot synthesis of 2,5-diarylimidazoles by palladium-catalyzed direct C–H arylation of 1-substituted imidazoles with aryl bromides have been devised. The first method, promoted by copper(I) iodide, is best suited for electron-poor aryl bromides, and also allows the 2,5-diarylation of thiazole and oxazole. The use of xylene instead of DMA is the key for the efficiency of the second
已经设计了两种通过钯催化1-取代的咪唑与芳基溴的直接C–H芳基化反应一锅合成2,5-二芳基咪唑的方法。由碘化铜(I)促进的第一种方法最适合于电子贫乏的芳基溴化物,并且还可以使噻唑和恶唑进行2,5-二芳基化。使用二甲苯代替DMA是提高第二种方法效率的关键,对于富电子的芳基溴化物,该方法可获得最佳结果。