A flame-dried 8 mL screw-capped tube was charged with [1.1.1]propellane in Et2O (1.0 equiv.). A solution of SF5Cl in n-pentane (1.5 equiv.) was added and the mixture was stirred under white LED irradiation at approx. 30 °C (estimated temperature based on proximity to the light source, ca. 2 cm) for 4 h. Purification of the final product was achieved via distillation: