Copper-Catalyzed Tandem Reactions of 2-Amine-[1,3,5]triazines with Nitriles

J Org Chem. 2019 Jan 18;84(2):536-543. doi: 10.1021/acs.joc.8b02150. Epub 2018 Dec 28.

Abstract

Copper-catalyzed intermolecular annulation of 2-amine-[1,3,5]triazines and aryl nitriles for the synthesis of [1,2,4]triazolo[1,5- a][1,3,5]triazines via N-C bond formation and oxidative N-N coupling [oxidative 3 + 2 cyclization] is presented. A wide range of aryl nitriles, including electron-rich benzonitriles, electron-poor benzonitriles, 2-cyanothiophene, and 4-cyanopyridine, were all functionalized with 2-amine-[1,3,5]triazines. Furthermore, amidation of 2-amine-[1,3,5]triazines via Cu-catalyzed C-CN bond cleavage of phenylacetonitriles is also demonstrated. The reaction occurred in moderate to satisfactory yields and tolerated alkyl- or aryl-substituted 2-amine-[1,3,5]triazines. Aniline, aminopyridine, and aminopyrimidine also afforded the desired products.