SYNTHESIS OF SPIROCYCLIC 3<i>Н</i>-PYRROL-4-AMINES FROM 2<i>H</i>-AZIRINES AND 1-SULFONYL-1,2,3-TRIAZOLES
DOI:
https://doi.org/10.1007/4776Keywords:
2Н-azirines, diazo compounds, pyrazines, pyrroles, spiro compounds, 1, 2, 3-triazoles, catalysisAbstract
The first derivatives of 3H-pyrrol-4-amines spiro-fused with fluorene or anthrone were synthesized in a Rh2(OAc)4-catalyzed reaction of 1sulfonyl-1,2,3-triazoles with 2H-azirines. The reaction proceeds through 1,4-diazahexa-1,3,5-triene intermediates, which under the conditions employed cyclize to stable at room temperature 1,2-dihydropyrazines. At elevated temperatures, 1,2-dihydropyrazines are in ring-chain equilibrium with 1,4-diazahexa-1,3,5-trienes, which undergo irreversible 5-exo-trig cyclization, leading to spirocyclic derivatives of 3H-pyrrol-4-amine.
Authors: Adel R. Khaidarov Nikolai V. Rostovskii, Galina L. Starova,
Alexander F. Khlebnikov, Mikhail S. Novikov