We began our investigation by applying a well-established strategy to generate SF5 radicals from SF5Cl (i.e., using catalytic BEt3/O2) in the presence of [1.1.1]propellane (1). The desired SF5-BCP-Cl product (2) was observed by F NMR in a promising 48% yield. This prompted an optimization campaign that led to the discovery that irradiating SF5Cl and 1 with white LEDs for 4 h would ultimately allow isolation of volatile 2 in 86% yield (Figure , top left). Based on previous literature on both SF5Cl and 1, a radical chain propagation mechanism is most likely at play following initial formation of SF5 radicals. Control experiments indicate that SF5Cl does not undergo decomposition under irradiation with white LEDs in the absence of 1, suggesting 1 is involved in the initiation step. Additionally, we isolated a minor byproduct (3) in 7% yield that incorporates two bicyclopentane motifs; similar types of dimerization products (i.e., " [2]staffanes") have been observed previously in radical chain processes involving 1. The calculated free energy profile at wB97XD/6-311++G** is also consistent with the observed selectivity, as the path from INT-1 to 2 is 14 kcal/mol more exergonic than to INT-2 (Figure , top right).