Abstract

Isoflavonoids constitute an important class of natural products, comprising great structural diversity. Known as phytoalexins and phytoestrogens, these compounds exhibit interesting biological activities. The corresponding carba-analogues, in which the oxygen atom at the B-ring is replaced by a methylene, are emerging as an attractive alternative for the preparation of new bioactive compounds. In this review, we report our results on the synthesis of isoflavonoid analogues (5-carba-pterocarpans, 1-carba-isoflavanones, 5-carba-11-aza-pterocarpan and pterocarpanquinones) with anti-cancer, antiparasitic and anti-viral properties. Palladium-catalyzed oxyarylation and azaarylation of dihydronaphthalenes and α-arylation of α- tetralones were the key steps in the developed synthetic approaches. A historical background, as well as a brief mechanistic discussion of these reactions, will be presented.

Keywords: Isoflavonoids, Carba-isoflavonoids, Oxyarylation, Azaarylation, α-Arylation, Palladium-catalyzed.

Graphical Abstract