Geminal Cross-Coupling of 1,1-Dibromoolefins Facilitating Multiple Topological π-Conjugated Tetraarylethenes

The cross-coupling reactions have been used in C-C bond formation which can be used extensively in optoelectronic materials for organic light-emitting diodes, organic photovoltaics, and chemical biosensing. Here, we report 2-fold geminal C-C bond formation at 1,1-dibromoolefins via cross-coupling reactions of aromatic boronic esters over Pd catalysts for multiple topological configurations of pi-conjugated molecules. We employ a series of recipes from a precursor toolbox to produce pi-conjugated macrocycles, conjugated dendrimers, linear conjugated polymers, and multiple conjugated microporous polymers and nanoparticles. The pi-conjugated macrocycles, dendrimers, and linear polymers show characteristic aggregation-induced emission properties. The conjugated microporous polymers possess unique porosity of 2-3 nm. The microporous polymer nanoparticles can be redispersed in solution. This universal strategy toward definite topological configurations of pi-conjugated molecules enables efficient coupling of aryl bromides with various coupling partners under mild conditions affording multiple topological conjugated systems with abundant optical and optoelectronic interest.