In the present work, an array of novel substituted 2H-chromen-2-one (coumarin derivatives abbreviated as C-337, C-480, C-540A) has been subjected to photophysical analysis. Although the influence of the electron donating groups such as amino, substituted amino, hydroxyl, alkoxy groups at position 7 of the coumarin ring system has been extensively studied, However, coumarin moieties with substit...

Coumarins are associated with a variety of pharmacological activities which have led to the synthesis of numerous derivatives. However, no general method for determination of the absolute configuration of chiral coumarins is known. This has now been achieved for a series of dihydrofuroangelicins bearing a variety of C-8 substituted double bonds, synthesized in the racemic form and resolved thro...

A highly enantioselective copper-catalyzed vinylogous propargylic substitution has been developed. Aromatic and aliphatic propargylic esters react smoothly with substituted coumarins under mild reaction conditions to give the desired products with excellent yields and enantioselectivities. Subsequent single-step transformations enable the synthesis of a wide range of multifunctional and diverse...

An efficient and convenient approach for one-pot synthesis of 3-substituted chroman-2,4-diones via a three-component reaction of aromatic aldehydes, 4-hydroxy-coumarins and diverse pyrazolone derivatives was described. The combinatorial synthesis for this methodology was achieved by applying ultrasound irradiation in the absence of activator while making use of water as green solvent. Additiona...

Abstract The base-catalyzed reaction of diethyl 1,3-acetonedicarboxylate with 2-hydroxybenzylidene indenediones was studied. provides a facile and expeditious protocol for the synthesis natural product inspired fluorenone-fused coumarins in good to very yields. This process resembles combination domino Michael–intramolecular Knoevenagel–aromatization–lactonization reactions single step. Althoug...

Free radicals and oxidants may cause various damages both to the lifeworld different products. A typical solution for prophylaxis of oxidation-caused conditions is usage antioxidants. Among them, classes are found—polyphenols, conjugated polyalkenes, some sulfur nitrogen derivatives. Regarding active site in molecules, a widely discussed group compounds 1,3-dicarbonyl compounds. them natural (e...