Substituted enamides were prepared by a three-component reaction of lithiated alkoxyallenes, nitriles, and carboxylic acids. Their subsequent condensation with ammonium salts provided alkoxy-substituted pyrimidine derivatives. This two-step method is highly flexible with respect to the substitution pattern at C-2 and C-6. The C-4 and C-5 positions can smoothly be functionalized employing either Pd-catalyzed couplings or oxidation methods.
通过石碳烯、腈和
羧酸的三组分反应,制备出了取代的烯酰胺。随后与
铵盐缩合,得到烷氧基取代的
嘧啶衍
生物。这种两步法在 C-2 和 C-6 位的取代模式方面非常灵活。通过 Pd 催化偶联或氧化方法,C-4 和 C-5 位可以顺利地进行官能化。