Journal of the American Chemical Society, Vol.118, No.5, 1028-1030, 1996
Novel Syntheses of Tetrahydropyrroloquinolines - Applications to Alkaloid Synthesis
Two novel routes involving the intramolecular olefin insertion with a zirconium--benzyne complex, followed by a palladium-catalyzed aryl amination, have been developed for the synthesis of tetrahydropyrroloquinolines. In one approach, exemplified in the six-step total synthesis of the South American toad poison dehydrobufotenine (1), the tricyclic system was formed via the Pd-catalyzed ring closure of a functionalized tryptamine derivative. In the second, cyclization of an appropriately substituted quinoline yields 13, an intermediate in the synthesis of damirones A and B, and also makaluvamine C, a topoisomerase II inhibitor exhibiting antitumor properties.
Keywords:SULFUR-CONTAINING ALKALOIDS;SPONGE PRIANOS-MELANOS;DISCORHABDIN-C;PYRROLOQUINOLINE ALKALOIDS;GENUS LATRUNCULIA;BATZELLA SP;INDOLES;CHEMISTRY;REAGENT