Synthesis of functionalised quinolines through tandem addition/annulation reactions of β-(2-aminophenyl)-α,β-ynones

Article abstract of DOI:10.1016/S0040-4020(99)00814-5

β-(2-aminophenyl)-α,β-ynones can quickly give functionalized 2,4-disubstituted quinolines through tandem nucleophic addition/annulations reactions. Acid-catalysed cyclization of β-(2-aminophenyl)-α,β-ynones can also occur. The easy entry into 4-iodo-2-substituted-quinolines prompted the development of a one pot procedure for synthesis of 2,4- disubstituted quinolines by further elaboration by means of palladium-catalysed reactions. The exposure to basic conditions of one β-(2-malonylamidophenyl)-α,β-ynone led to a fused quinolone derivative through intramolecular Michael addition/tautomerisation/transesterification cascade reactions. Fused polycyclic quinolines can be viewed as occurring through a tandem concerted Diels-Alder/annulation reactions of β-(2- aminophenyl)α,β-ynones with enamines, azides and nitrile oxides.