Sulfur dioxide is not only a useful building block in a synthetic organic chemistry, but in its liquid state (SO2(liq.)) can be used as a strong polar solvent as well. Combination of In(III) or Hf(IV) triflate as a catalyst and SO2(liq.) as a solvent allowed us to obtain desired arylketones in good to excellent yields without direct addition of acid. Hydrohalogenation of alkynes by LiBr/H2O or NH4I in SO2(liq.) provided up to almost quantitative conversion of starting material into the desired vinyl halide.