Facile Synthesis of Diversified Biisoquinoline-Containing Polymers by Multicomponent C─H Activation/Annulation...

Biisoquinoline scaffolds with unique photophysical properties and latent axial chirality have received considerable attention in medical chemistry, asymmetric catalysis, and materials science. However, limited by the large synthetic difficulties, functional biisoquinoline-containing polymers (BCPs) have rarely been reported. Furthermore, the construction of optically active BCPs via asymmetric catalytic polymerization have not been achieved so far. Herein, we developed a multicomponent cascade C─H activation/annulation polymerization (CAAP) strategy that can facilely convert readily available benzil derivatives, internal diynes, and ammonium acetate into structurally diverse BCPs via successive C─H activation and N-annulation processes in a one-pot and one-step operation. The rhodium-catalyzed CAAP reactions proceed efficiently under air, affording a variety of multisubstituted BCPs with high molecular weights (M_w up to 49900 g mol^-1) in good yields. Benefiting from the unique structures, the resulting BCPs exhibit excellent solubility, good film-forming capability, and readily tunable luminescent properties. The luminescent thin films of a photosensitive BCP can be applied for the generation of multiscale fluorescent photopatterns with high resolution. Moreover, by using different chiral cyclopentadienyl rhodium catalysts, a series of optically active BCPs and BCP-metal complex with stable axially chiral configurations are in situ generated from the asymmetric CAAP reactions.