Molecular iodine: A versatile catalyst for the synthesis of bis(4-hydroxycoumarin) methanes in water

A Rapid, Efficient and Green Method for Synthesis of 3,3'-Arylmethylene-bis-4-hydroxycoumarins without Use of any Solvent, Catalyst or Solid Surface

“…It is the hemorrhagic agent responsible for the sweet clover disease of cattle and has also been employed for the prevention and treatment of thrombosis 12 . 3,3'-Arylmethylene-bis-4-hydroxycoumarins (3) are usually synthesized by condensing 4-hydroxycoumarin (1) with various aldehydes (aromatic, heterocyclic and α,β-unsaturated) (2) using different catalysts and media [8][9][10][13][14][15][16][17][18][19] . Some of these methods require long reaction time, use of expensive catalysts and organic solvents and tedious work up 8,10 .…”

“…Some of these methods require long reaction time, use of expensive catalysts and organic solvents and tedious work up 8,10 . The current literature shows that there has been a growing trend towards green synthesis of these compounds [13][14][15][16][17][18][19] . However, in such reported green methods use of catalysts, solid surfaces, solvents etc.…”

A Highly Efficient and Fast Method for the Synthesis of Biscoumarins Using Tetrabutylammonium Hexatungstate [TBA]2[W6O19] as Green and Reusable Heterogeneous Catalyst

“…6 Recently, a number of methods have been reported for the synthesis of biscoumarins by reaction of 4-hydroxycoumarin and various aldehydes. [7][8][9][10][11] Although these methods may be effective, some of them have relatively long reaction times, and unsatisfactory yields. These finding prompted us towards further investigation in search for a new catalyst, which will carry out the synthesis of biscoumarins under simpler experimental set up and eco-friendly conditions.…”

Silica Chloride Nano Particle Catalyzed Synthesis of 2,2'-(arylmethylene)bis(5,5-dimethylcyclohexane-1,3-dione) Derivatives

“…2 There are several methods reported for the synthesis of 2,2′ -(arylmethylene)bis(5,5-dimethylcyclohexane-1,3-dione). [3][4][5][6] These reactions have been reported at catalyzed conditions for example SDS, 6b molecular iodine, 4 HClO 4 -SiO 2 and PPA-SiO 2 (Ref.…”