Diels-Alder Reactions of (1H-Indol-3-yl)-enacetamides and -endiacetamides: A Selective Access to Acetylamino-Functionalized Annelated Indoles and Carbazoles

Article abstract of DOI:10.1002/hlca.19910740406

Diels-Alder reactions of the (1H-indol-3-yl)-enacetamides and -endiacetamides 1a - d with some carbodienophiles and 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione give rise to the novel amino-functionalized carbazoles 4 - 6 and 8 (Scheme 3).Ethenetetracarbonitrile reacts with 1b to furnish the Michael-type adduct 7 (Scheme 3).Structural aspects of the starting materials 1, which exhibit above all 3-vinyl-1H-indole reactivity, are discussed with regard to the prediction of a Diels-Alder process.