The Heck coupling reaction using aryl vinyl ketones: Synthesis of flavonoids

In our previous communication, an alpha,beta-unsaturated aryl ketone was employed as the substrate olefin, which underwent arylation in the Heck coupling reaction. The use of this reagent has allowed us to design a new strategy for the synthesis of flavonoids. In this paper, we illustrate the versatility of the procedure, which was used for the preparation of several chalcones. According to our synthetic scheme, several aryl iodides, selected in order to obtain chalcones differently substituted in ring B, were treated with alpha,beta-unsaturated ketones. All reported syntheses gave high yields. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.