Synthesis of reactively functionalized 2,5-siloles using kumada-type nickel-mediated intramolecular cyclization and their utilization in polymer synthesis

The syntheses of reactively functionalized 2,5-siloles by the Kumada-type nickel-catalyzed intramolecular cyclization of alkynes and disilane, and their subsequent polymerization with diketopyrrolopyrrole (DPP) are described. The prefunctionalization of the 2,5-positions of the silole ring, which avoids the problem of silole susceptibility to nucleophiles during post-modification highlights this synthesis. Suzuki, Stille, and direct arylation silole precursors were prepared by this reaction and were subsequently subjected to polymerization with DPP by the various polymerization methods. The polymers all had reduced bandgaps (Eg