Abstract

Chalcones are the main precursors for the biosynthesis of flavonoids and isoflavonoids. Chalcones comprise of a three carbon α, β-unsaturated carbonyl system. These are the condensation products of aromatic aldehyde with acetophenones in the presence of catalyst. They go through a variety of chemical reactions and are found beneficial in synthesis of pyrazoline, isoxazole and an assortment of heterocyclic compounds. Chalcones play pivotal role in synthesizing a range of remedial compounds. They have exhibited impressive curative efficacy for the treatment of numerous diseases. Chalcone based derivatives have gained focus since they possess simple structures and sundry pharmacological actions. A number of techniques and schemes have been reported for the synthesis of these compounds. Amongst all the stated methods, Aldol condensation and Claisen-Schmidt condensation still hold high position. Other renowned techniques include Suzuki reaction, Witting reaction, Friedel-Crafts acylation with cinnamoyl chloride, Photo-Fries rearrangement of phenyl cinnamates etc. These innovative techniques employ various catalysts and reagents including SOCl2 natural phosphate, lithium nitrate, amino grafted zeolites, zinc oxide, water, Na2CO3, PEG400, silicasulfuric acid, ZrCl4 and ionic liquid etc. The development of improved strategies for the synthesis of α, β- unsaturated carbonyl compounds is still in demand. Briefly, we have explained the methods and catalysts used in the synthesis of chalcones in a review form to provide information for the development of new-fangled processes aiming better yield, less reaction time and minimum side effects.

Keywords: Chalcones, claisen-schmidt condensation, flavonoids, anticancer, anti- inflammatory