A novel Palladium based heterogenous catalyst for tandem annulation: A strategy for direct synthesis of acridones

H. SEBASTIÁN STEINGRUBER; PAMELA MENDOROZ; M. JULIA CASTRO; MARÍA A. VOLPE; DARÍO C. GERBINO

SYNTHESIS-STUTTGART

GEORG THIEME VERLAG KG

Año: 2022 vol. 54 p. 692 - 706

0039-7881

In order to develop an efficient, rapid and modular cascade strategy for the direct synthesis of acridones, palladium supported on sulfated alumina and microwave activation are employed. Multifunctional heterogeneous palladium catalysts were prepared in order to carry out the sequential annulation via a Buchwald-Hartwig amination followed by an intramolecular annulation in a one-pot process. This new protocol represents the first report on a catalytic tandem synthesis of acridone derivatives from commercially available starting materials, under ligand-free conditions. The scope of the present methodology is extended to the generation of a library of functionalized acridones, showing high functional group compatibility, in moderate to excellent yields. The applicability of this novel transformation was demonstrated by the concise total synthesis of the natural product arborinine