A divergent efficient assembly of disubstituted 1,2,4-triazoles was established by cyclization of readily accessible N′-nitro-2-hydrocarbylidene-hydrazinecarboximidamides with moderate to excellent yields under mild reaction conditions. This divergent synthetic strategy was achieved simply by varying the reaction conditions. Under acidic conditions, amino-1,2,4-triazoles were obtained by an intramolecular
通过在温和的反应条件下以中等至极好的收率将易于获得的N'-硝基-2-亚烃基-
肼甲二
酰亚胺环化,可以建立二取代的
1,2,4-三唑的不同有效组装。仅通过改变反应条件就可以实现这种多样化的合成策略。在酸性条件下,通过涉及NO 2基团的分子内
氧化还原反应获得
氨基-
1,2,4-三唑。对照实验和DFT研究表明,这种转化过程是通过分子内的1,3-
氢化物转移途径进行的,从而消除了
HNO2。在中性条件下,以
水为溶剂,通过在空气中
氧化分子内环化获得硝基亚
氨基-1,2,4-三唑。