Zn[(L)Proline]2: an eligible candidate for the synthesis of xanthenediones in water

An efficient route for the condensation of aldehydes with dimedone in the presence of Zn[(L)Proline]2 in water has been reported. Hydrophilicity of the catalyst is the main attribute of this reaction. The water-mediated reaction using catalytic amounts of recyclable catalyst avoids the use of expensive, corrosive reagents and toxic solvents and provides operational simplicity. Moreover, column chromatography and recrystallization of product are not required as the crude products itself are very pure and hence can be used for target-oriented synthesis on a large scale. Copyright (c) 2012 John Wiley & Sons, Ltd.