Microwave-assisted synthesis of xanthones promoted by ytterbium triflate

Xanthones represent a class of naturally occurring compounds with valuable and promising reported pharmacological activities. One of the main disadvantages in the use of such products is related to the difficulties in their chemical synthesis. In this Letter a new and improved method for the chemical synthesis of xanthones is described. The title compounds have been synthesized in good yields under microwave irradiation from substituted 2-hydroxybenzoic acids and phenols in the presence of Yb(OTf)(3) hydrate as the catalyst. (C) 2014 Elsevier Ltd. All rights reserved.