Preparation of synthetic and natural flavonoids

We developed a new method for the mild and selective bromination of simple aromatic compounds and flavonoids in good yields using α,β-dibromohydrocinnamic acid in the presence of a base. This procedure enables selective mono- or dibromination of compounds highly sensitive to oxidative or radical attack. New brominated derivatives of silymarin flavonolignans and related flavonoids were prepared. These brominated derivatives can be used as valuable synthetic intermediates in further synthesis (Hurtová 2020).


Scheme 1. Scheme of the bromination employing α,β-dibromohydrocinnamic acid


Halogenated derivatives were later used as starting materials for palladium-catalyzed cross-coupling reactions. We prepared a library of derivatives substituted at C-8 with aryl and alkyl- substituents (Hurtová 2022).


Scheme 2. General scheme for the cross-coupling reaction



Financial support

This work was supported by Czech Science Foundation (project No. 21-00551S).