Architecting a Bismacrocycle through a Single C–C Bond Connection

High Resolution Image Download MS PowerPoint Slide The covalent linkage of preformed supramolecular entities represents a powerful yet synthetically challenging strategy for constructing sophisticated functional systems, crucial for advances in enzyme mimicry, catalysis, and materials. Addressing the core difficulty of precise, site-selective coupling, we report a direct one-step C–C coupling of carbazole-based macrocycles 2 under Scholl reaction conditions to afford bismacrocycle 1 . Interestingly, when using the smaller ring precursor 4 under similar reaction conditions, we obtain the intermolecular dehydrogenative product 3 . DFT computations provide insight into the distinct formation pathways of monomacrocycle 3 and bismacrocycle 1 . Moreover, we investigated the photophysical properties of compounds 1 – 4, confirming that all are suitable hosts for C 70, with their binding constants determined. Notably, bismacrocycle 1 demonstrates exceptional photocatalytic activity for debrominative borylation, outperforming other macrocycles ( 2 – 4 ) in catalytic efficiency. Finally, we also examined the anticancer activities of these newly synthesized macrocycles. Collectively, this work provides a versatile synthetic strategy for a complex bismacrocycle and establishes its significant dual potential as a selective host, a powerful photocatalyst, and a photocytotoxic anticancer candidate.