Catalytic B–C Coupling by Si/B Exchange: A Versatile Route to π‑Conjugated Organoborane Molecules, Oligomers, and Polymers

Conjugated
organoboranes have emerged as attractive hybrid materials
for optoelectronic applications. Herein, a highly efficient, environmentally
benign catalytic B–C bond formation method is presented that
uses organosilicon compounds, dibromoboranes, and the metal-free organocatalyst
Me3SiNTf2. This Si/B exchange approach has been
successfully applied to the synthesis of arylborane molecules 4a–c, oligomers 8a,b, and polymers 8a′,b′. Photophysical investigations, supported by TD-DFT calculations,
reveal highly effective π-conjugation in thienyl- and furylborane
species; the latter are also highly emissive.