Synthesis 2023; 55(04): 692-706
DOI: 10.1055/s-0042-1751371
paper

A Novel Palladium-Based Heterogeneous Catalyst for Tandem Annulation: A Strategy for Direct Synthesis of Acridones

H. Sebastián Steingruber
a   Instituto de Química del Sur, INQUISUR (CONICET-UNS), Departamento de Química, Universidad Nacional del Sur, Avenida Alem 1253, 8000 Bahía Blanca, Argentina
,
Pamela Mendioroz
a   Instituto de Química del Sur, INQUISUR (CONICET-UNS), Departamento de Química, Universidad Nacional del Sur, Avenida Alem 1253, 8000 Bahía Blanca, Argentina
,
M. Julia Castro
a   Instituto de Química del Sur, INQUISUR (CONICET-UNS), Departamento de Química, Universidad Nacional del Sur, Avenida Alem 1253, 8000 Bahía Blanca, Argentina
,
María A. Volpe
b   Planta Piloto de Ingeniería Química (PLAPIQUI-CONICET), Camino La Carrindanga Km 7, 8000 Bahía Blanca, Argentina
,
Darío C. Gerbino
a   Instituto de Química del Sur, INQUISUR (CONICET-UNS), Departamento de Química, Universidad Nacional del Sur, Avenida Alem 1253, 8000 Bahía Blanca, Argentina
› Institutsangaben
This work was generously supported by the National Council of Scientific­ and Technical Research (Consejo Nacional de Investigaciones Científicas y Técnicas; CONICET), the National Agency for Scientific­ and Technological Promotion (Agencia Nacional de Promoción Científica y Tecnológica; ANPCyT), and the Universidad Nacional del Sur (Secretaría General de Ciencia y Tecnología, Universidad Nacional­ del Sur; SGCyT-UNS), Argentina.


Dedicated to Professor Hans-Günther Schmalz on the occasion of his 65th birthday

Abstract

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.

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Eingereicht: 29. Juli 2022

Angenommen nach Revision: 12. September 2022

Artikel online veröffentlicht:
11. Oktober 2022

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