A Review of Synthesis Methods of Chalcones, Flavonoids, and Coumarins

Abstract

Chalcones are the principal precursors for the biosynthesis of flavonoids and isoflavonoids. A three-carbon α, β-unsaturated carbonyl system constitutes chalcones. Chalcones are the condensation products of an aromatic aldehyde with acetophenones in attendance of catalyst. A lot of methods and schemes have been reported for the synthesis of these compounds. Amongst all, Aldol condensation and Claisen-Schmidt condensation reactions are the most cited synthetic protocols in literature, nevertheless, Suzuki reaction, Witting reaction, and Photo-Fries rearrangement have also been utilized as synthetic protocols towards the chalcone framework. Several catalysts have been developed in the synthesis of the chalcone framework among which SOCl₂ natural phosphate, lithium nitrate, amino grafted zeolites, zinc oxide, water, K₂CO₃, PEG400, silica sulfuric acid, ZrCl_4, and ionic liquid are the most cited ones. The development of better synthetic techniques for the synthesis of α, β- unsaturated carbonyl compounds is still remaining high demand.

Keywords: Chalcones, Aldol condensation, Claisen-Schmidt condensation, Suzuki reaction, Witting reaction, Photo-Fries rearrangement

DOI: 10.7176/CMR/14-3-01

Publication date:August 31^st 2022