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

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, ZrCl4, 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 31st 2022