Application of the intramolecular Diels-Alder vinylarene (IMDAV) reaction for the synthesis of benzo-and carbocyclofuroisoindolecarboxylic acids and its limitations

Abstract

Furylallylamines, readily accessible from the corresponding furylacroleines, react with maleic, citraconic and trifluoromethylmaleic anhydrides to form acids with a furo[2,3-f]isoindole core.The reaction sequence involves two successive steps: the acylation of the nitrogen atom of the initial allylamine and the intramolecular Diels-Alder vinylarene (IMDAV) reaction. The scope and limitations of the proposed method were thoroughly investigated. The key step, the IMDAV reaction, proceeds through an exo-transition state, giving rise to the exclusive formation of a single diastereomer of the target heterocycle. Functionally substituted furo[2,3-f]isoindole carboxylic acids are potential substrates for further transformation.