Polymer anchored ruthenium complex: A highly active and recyclable catalyst for one-pot azide–alkyne cycloaddition and transfer-hydrogenation of ketones under mild conditions

Abstract

A new polymer supported Ru(III) complex has been synthesized and characterized. The catalytic performance of the complex has been tested for the first time azide–alkyne cycloaddition reaction in water and transfer-hydrogenation reaction of ketones in open air. 1,4-disubstituted-1,2,3-triazoles were obtained in excellent yields from azides and terminal alkynes in aqueous medium in the presence of the above catalyst. Aromatic ketones have been converted to their corresponding alcohols using the polymer supported Ru(III) catalyst. The effects of solvents, reaction time, catalyst amount for the azide–alkyne cycloaddition reaction and transfer-hydrogenation reaction were studied. This catalyst showed excellent catalytic activity and recyclability. The polymer supported Ru(III) catalyst could be easily recovered by filtration and reused more than five times without appreciable loss of its initial activity. There was no evidence of leached Ru from the catalyst during the course of reaction has been observed, suggesting true heterogeneity in the catalytic process.