Rhodium-Catalyzed Stitching Reaction: Convergent Synthesis of Quinoidal Fused Oligosiloles.

Abstract

Quinoidal fused oligosiloles, a new family of silicon-bridged π-conjugated compounds, have been synthesized for the first time based on a new synthetic strategy, a stitching reaction. Multiple carbon-carbon bonds can be formed consecutively between two oligo(silylene-ethynylene)s under rhodium catalysis in a stitching manner, and up to five siloles have been fused in a quinoidal form. Physical properties of these oligosiloles have also been investigated to find a unique trend in their LUMO levels, which become higher with longer π-conjugation.