Expedious synthesis for α, β-unsaturated coumarin derivatives using boran chelates: A novel class of potential antibacterial and antioxidant agents

A new family of coumarin derivatives (4a-i) containing a chalcone moiety was synthesized by condensation of 3-acetyl-4-difluoro boryloxycoumarin (2) with aryl and heteroaryl aldehydes with piperidine in chloroform. Resulting compounds were characterized by IR, (13)C, (1)H NMR and UV visible spectroscopy. Compound 3-((2E)-3-(3,4,5-Trimethoxy-phenyl)prop-2-enoyl)-2(H)-chromen-2-one (4g) was characterized by single crystal X-ray diffraction. The antioxidant and antibacterial activities of the obtained compounds 4a-i was evaluated. The biological activity found for these compounds is discussed against their structural features, physical and chemical properties. (C) 2009 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.