First syntheses of two quinoline alkaloids from the medicinal herb Ruta chalepensis via cyclization of an o-iodoaniline with an acetylenic sulfone

The first syntheses of two quinoline alkaloids found in the medicinal herb Ruta chalepensis are reported via the conjugate addition of an o-iodoaniline to an acetylenic sulfone, followed by Pd-catalyzed carbonylation, intramolecular acylation of the corresponding sulfone-stabilized carbanion, and reductive desulfonylation.