Metal-free One-pot Synthesis of 1,2,4-Triazolo[4,3-<i>a</i>]pyridines from 2-Hydrazinylpyridines
作者:L. Madhava Reddy、V. Veerabadra Reddy、P. Sai Prathima、Ch. Krishna Reddy、B. V. Subba Reddy
DOI:10.1002/adsc.201800512
日期:2018.8.17
A metal‐free one‐pot strategy has been developed for the synthesis of 3‐aryl[1,2,4]triazolo[4,3‐a]pyridines through an oxidative cyclization of 2‐(2‐arylidenehydrazinyl)pyridines by utilizing molecular iodine in DMSO. This is the first report on the synthesis of 3‐aroyl[1,2,4]triazolo[4,3‐a]pyridines directly from α‐aryl methyl ketones or ethyl benzoylacetate or styrenes or phenylacetylenes and 2‐hydrazinylpyridines
已开发出一种无金属的单锅策略,该方法通过利用分子间的2-(2-亚芳基肼基嗪)吡啶的氧化环化反应来合成3-芳基[1,2,4]三唑并[4,3- a ]吡啶DMSO中的碘。这是第一个关于直接由α-芳基甲基酮或苯甲酰乙酸乙酯或苯乙烯或苯乙炔和2-羟基苯并吡啶经碘促进的氧化法合成3-芳基[1,2,4]三唑并[4,3- a ]吡啶的报告。环化。碘的催化使用使该方法相当简单,更加方便和经济。而且,该方案在温和的反应条件下显示了较宽的底物范围,可以取代危险金属试剂的使用。