an efficient method has been developed for the catalysis of condensation of 1,2-phenylenediamines and 2-aminothiophenoles with different aldehydes into their corresponding 2-aryl-1h-benzimidazoles and 2-aryl-1h-benzothiazoles under mild condition. in this method, trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane (dhpdmdo)/hoac/ki system was used as a novel and effective oxidant in water at roo...