RESUMEN
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.
RESUMEN
An efficient copper-catalyzed synthesis of substituted 2,4-diamino-1,3,5-triazines from 1,1-dibromoalkenes and biguanides under mild conditions has been developed. The reaction occurred in moderate to good yields and tolerated alkyl-, heterocyclic-, or aryl-substituted 1,1-dibromoalkenes containing functionalities such as nitriles, ethers, and halogens. Monosubstituted to tetrasubstituted biguanidines also afforded the desired products.
