1.
Org Lett
; 25(43): 7847-7851, 2023 Nov 03.
Artigo
em Inglês
| MEDLINE
| ID: mdl-37879081
RESUMO
Pyrazines are reactive 4π partners in intermolecular Diels-Alder cycloaddition with exceptionally activated dienophiles or in an intermolecular version at elevated temperatures. Herein, it is shown that an intramolecular cascade could occur even at room temperature, delivering a collection of 6- or 7-aza-indazoles. An interesting substituent effect of the cycloaddition precursor on the product distribution was uncovered, and in situ NMR studies were conducted to gain insights into this unexpected selectivity.