Trifluoromethylation of Aromatic Isoxazoles: Regio- and Diastereoselective Route to 5-Trifluoromethyl-2-isoxazolines
作者:Hiroyuki Kawai、Kentaro Tachi、Etsuko Tokunaga、Motoo Shiro、Norio Shibata
DOI:10.1002/anie.201102442
日期:2011.8.16
It all adds up: The activation of aromatic isoxazoles with a nitro group at the 4‐position has enabled the first regio‐ and diastereoselective trifluoromethylation at the 5‐position of isoxazoles by nucleophilic addition using Me3SiCF3 (see scheme; DMF=N,N′‐dimethylformamide). The process was demonstrated with a broad range of 3,5‐aromatic, heteroaromatic and aliphatic substrates.
所有这些加起来:在4位上带有硝基的芳香异恶唑的活化,使得能够通过Me 3 SiCF 3的亲核加成在异恶唑的5位上进行第一次区域和非对映选择性的三氟甲基化(参见方案; DMF = N ,N'-二甲基甲酰胺)。广泛的3,5-芳族,杂芳族和脂族底物都证明了该方法。