Given the low cost of the gaseous components, we adjusted the stoichiometry by adding three equivalents of SO2, resulting in a high yield for the transformation, with benzyl bromide serving as the limiting reagent ( power) for 1 h. The outflow is collected in a flask containing NaHCO3 (1.0mmol) and benzyl bromide (0.6 mmol, 1.5 equiv.) and is stirred overnight at room temperature. Yield determined by 1 H-NMR spectroscopy using trichloroethylene as external standard. Optimized conditions: SO2 (0.6 mmol), propane (3.0 mmol), DT catalyst (1 mol%) in CH3CN/H2O (4:1, 3 mL, 0.2M) irradiated in photoreactor (365 nm, 144 W optical output power) for 1 h. The outflow is collected in a flask containing NaHCO3 (1.2 mmol) and benzyl bromide (0.2 mmol, 1 equiv.) and is stirred overnight at room temperature.