Application Of Heterocyclic Ketene Aminals In Heterocyclic Compounds Construction

Heterocyclic ketene aminals (HKAs) are versatile building blocks and active skeleton in organic chemistry. In this context, based a survey of literature and the concept of Diversity-Oriented Synthesis, we comprehensively studied the reaction diversity of HKAs. Consindering the availability of electron withdrawing group (EWG) and the phenomenon that the a-carbon and the secondary amino groups usually react with bis-electrophiles to produce the fused heterocyclic, we studied the reaction diversity of HKAs. And 1,8-naphthyridine derivatives, indenofurans and indenopyridines were gained through a one pot, three-component protocol.1. An efficient and versatile method was developed for the access of multisubstituted 1,8-naphthyridine derivatives through a one pot, three-component protocol from heterocyclic ketene animals,malononitrile dimer, and aryl aldehydes in high yields. Based on the different effect that different catalysts have, piperidine and acetic acid were selected as the co-catalyst in this method. The 1,8-naphthyridines were formed via Knoevenagel condensation, aza-ene reaction, imine-enamine tautomerization, and intramolecular cyclization.2. An efficient and concise method was developed for access to indenofurans and indenopyridines through a one pot, three-component protocol from heterocyclic ketene aminals, o-phthalaldehyde and 1,3-diketones under catalyst-free conditions. The ring size of HKAs plays an important role in the regioselective reaction. The indenofurans and indenopyridines were formed via aldol condensation, a regioselective aza-ene reaction, imine-enamine tautomerization and intramolecular cyclization.