Abstract Using electron-positron annihilation data samples corresponding to an integrated luminosity of 4.5 fb , collected by the BESIII detector in the energy region between and , we report the first observations of the Cabibbo-suppressed decays , , and the Cabibbo-favored decay with statistical significances of , , and , respectively. The branching fractions of these decays are measured to be %, %, and %, where the first uncertainties are statistical and the second are systematic. We find that the branching fraction of the decay is about one order of magnitude higher than that of .