A new method was developed to transform alkenes into three types of functional molecules, including epoxides, aldehydes and 1,2-diols by using dichlororuthenium(IV) meso-tetrakis(2,6-dichlorophenyl)porphyrin [Ru(IV)(TDCPP)Cl2] as catalyst and 2,6-dichloropyridineN-oxide (Cl2pyNO) as the oxidant, in which the 1,2-diols were afforded via “one-pot” reactions in moderate yields.