One-Step Synthesis of Xanthones Catalyzed by a Highly Efficient Copper-Based Magnetically Recoverable Nanocatalyst

Abstract

A versatile and highly efficient strategy to construct a xanthone skeleton via a ligand-free intermolecular catalytic coupling of 2-substituted benzaldehydes and a wide range of phenols has been developed. For this purpose, a novel and magnetically recoverable catalyst consisting of copper nanoparticles on nanosized silica coated maghemite is presented. The reaction proceeds smoothly with easy recovery and reuse of the catalyst. The methodology is compatible with various functional groups and provides an attractive protocol for the generation of a small library of xanthones in very good yield.

Xanthone from the Fruits of <I>Terminalia Arjuna</I>

“…1 A signal appeared as singlet at  H 3.82 integrated for six protons were assigned for two methoxy groups. Thus, the structure of compound 1 was established as 2,7-dimthoxyxanthone which was synthesized by en ndez and ahfouz and their co-worker [25,26]. Compound 1 was isolated first time from any natural source.…”

“…Herein we report the isolation for the first time and structure elucidation of a known compound from Terminalia arjuna. The structure was identified on the basis of 1 H and 13 C NMR experiments and mass spectroscopic data, UV, FTIR and by comparison with the authentic data of the compound published in the literatures [25,26].…”

The Role of Green Solvents and Catalysts at the Future of Drug Design and of Synthesis

“…One-step synthesis of xanthones was achieved by Gerbino and coworkers in which copperbased magnetically recoverable nanocatalyst was utilized [49]. Salicylaldehyde and phenol derivatives were reacted in toluene under ligand-free condition (Scheme 21).…”

Synthesis of Xanthones by Palladium‐Catalyzed Tandem Carbonylation/C–H Activation via 2‐Iodo Diaryl Ethers

“…The first is the “classical method” involving an intramolecular S N Ar or Friedel–Crafts reaction . Since the 1980s, transition‐metal‐catalyzed C–H bond activation of the derivatives of diaryl ether, as the second methodology to form xanthones, has been developed remarkably in the synthesis of xanthones . Intriguingly, Larock reported a tandem coupling–cyclization of arynes to xanthones as a strategy to construct a phenyl ring.…”