Search

An efficient cascade strategy for the direct synthesis of pyrrolo[3,2,1-de]acridones 4a-v, 5a-h from iodo-pyranoquinolines 2a-i by the palladium-catalyzed regioselective [3 + 2] alkyne annulation/ring-opening followed by intramolecular aldol condensation under microwave irradiation is described. The chemistry involves the in situ formation of pyrroloquinolines Y, via palladium-catalyzed selective [3 + 2] annulation of iodopyranoquinolines and internal akynes with ring-opening and successive intramolecular cross-aldol condensation. Both the symmetrical and unsymmetrical internal alkynes were reacted smoothly to provide the desired pyrroloacridones in good yields. This methodology provides the facile conversion of easily accessble iodopyranoquinoline into highly functionalized biologically important pyrroloacridones in a single process.

A regioselective tandem synthesis of highly functionalized pyrrolo[1,2-a]quinolines has been developed through a novel strategy by palladium-catalyzed [3 + 2] annulation of iodo-pyranoquinolines and internal alkynes with subsequent ring opening. Pyranoquinoline with n-alkyl substitution at the 3-position leads to the formation of pyrrolo-acridones via [3 + 2] annulations/ring opening and successive intramolecular cross-aldol condensation.

The Rh(III)-catalyzed oxidative coupling of 2-aryl-imidazopyridines with internal alkynes via double C–H activation has been described. This approach provides straightforward access to highly functionalized polycyclic imidazopyridines in good to excellent yields. [ABSTRACT FROM AUTHOR]

Oxidative coupling of 2-aryl-imidazopyridines with alkynes affords polycyclic imidazopyridines. [ABSTRACT FROM AUTHOR]