Light-enabled metal-free carbo- and silyl functionalization of [1.1.1]propellane and [3.1.1]propellane

1,3-Disubstituted bicyclo[1.1.1]pentanes (BCPs) have emerged as privileged scaffolds in pharmaceutical discovery and functional materials, often employed as bioisosteres of para-disubstituted benzenes. Existing synthetic approaches to these motifs typically rely on muti-step sequences or multi-component reactions and frequently require the participation of transition metals, photocatalysts and radical initiators. Herein, we report a modular and transition metal-free strategy for the synthesis of 1,3-disubstituted BCPs directly from [1.1.1]propellane through sequential C-C bond formation. The protocol enables efficient access to dichloro- and trichloro-substituted BCPs, which represent underexplored yet promising scaffolds for drug discovery. The strategy could be further extended to [3.1.1]propellane, affording 1,5-disubstituted bicyclo[3.1.1]heptanes (BCHs). Notably, this approach could also be extended to C-Si bond formation, providing rare silyl-substituted BCPs with potential applications in material science. Overall, this work establishes a general, catalyst-free platform for the modular functionalization of highly strained propellanes.