Chemoselective Synthesis of 5-Alkylamino-1<i>H</i>-pyrazole-4-carbaldehydes by Cesium- and Copper-Mediated Amination
作者:Jessica Orrego-Hernández、Justo Cobo、Jaime Portilla
DOI:10.1002/ejoc.201500505
日期:2015.8
Microwave-assisted synthesis of new 5-alkylamino-pyrazole-4-carbaldehydes was performed efficiently, with yields up to 99 % and short reaction times. Nucleophilic substitution of primary alkylamines with activated 5-chloro-1-(2-pyridyl)pyrazole-4-carbaldehyde was mediated by the “cesium effect”. The amination of deactivated 1-aryl-5-chloropyrazole-4-carbaldehydes was also assisted by the cesium ion
新型 5-烷基氨基-吡唑-4-甲醛的微波辅助合成高效进行,产率高达 99%,反应时间短。伯烷基胺与活化的 5-氯-1-(2-吡啶基)吡唑-4-甲醛的亲核取代是由“铯效应”介导的。失活的 1-芳基-5-氯吡唑-4-甲醛的胺化也得到铯离子的辅助和铜(I)的催化。