Contrary to the common idea that Fischer indole cyclization often cannot be effectively applied to the synthesis of the corresponding azaindoles, we show that this approach can be actually very efficient for the formation of 4- and 6-azaindoles bearing an electron-donating group on the starting pyridylhydrazines. Two 4-azaindole natural product analogues were synthesized in a few steps and very good
与通常认为Fischer
吲哚环化通常不能有效地用于合成相应的氮杂
吲哚的普遍观点相反,我们证明了这种方法实际上对于形成在其上带有给电子基团的4-和
6-氮杂吲哚非常有效。起始
吡啶基
肼。通过几个步骤合成了两个
4-氮杂吲哚天然产物类似物,并且具有很高的总收率。