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

Molecular iodine has been used an efficient catalyst for an improved and rapid one-pot synthesis of 3,3'-arylmethylenebis-(4-hydroxycoumarin) and 2,2'-arylmethylenebis(3-hydroxyl-5,5-dimethyl-2-cyclohexen-1-one) in excellent yields using water as a reaction medium. This aqua mediated Michael addition of various aromatic and heteroaromatic aldehydes with 4-hydroxycoumarin or dimedone using catalytic amount of molecular iodine devoids the use of expensive, corrosive reagents, toxic sovents and provides the operational simplicity