Base-promoted aromatic [3,3] sigmatropic rearrangement of N-acyl-O-arylhydroxylamine derivatives
作者:Eiji Tayama、Kazuki Hirano
DOI:10.1016/j.tet.2018.12.058
日期:2019.2
temperature generated the corresponding amide enolates. The aromatic [3,3] rearrangement of the enolates provided the desired products in moderate to good yields. A crossover experiment produced only intramolecular products and clarified that the reaction proceeds via the aromatic [3,3] sigmatropic rearrangement, not a bond-cleavage–recombination process. Our method is a formal α-arylation of amides.
成功地证明了碱促进的N-酰基-O-芳基羟胺的芳香族[3,3]σ重排,得到α-(2-羟苯基)酰胺。由N-取代的羟胺先进行N-酰化,再由铜(I)介导的O制备底物-与硼酸芳基化。在0°C至室温下,在THF中用六甲基二硅叠氮化锂(LiHMDS)处理底物,生成相应的酰胺烯酸酯。烯醇化物的芳族[3,3]重排以中等至良好的产率提供了所需的产物。交叉实验仅产生分子内产物,并澄清了反应是通过芳香族[3,3]σ重排进行的,而不是通过键断裂-重组过程进行的。我们的方法是酰胺的形式α-芳基化。