Synthesis and characterization of optically active helical poly(α, β-unsaturated ketone) with bulky pendant of binaphthyl

The synthesis and chiroptical properties of a novel optically active helical polymers, poly[(S)-6-acryloyl-2,2′-bisalkoxy-1,1′-binaphthyl] (poly-3), were reported. All the monomers readily underwent anionic polymerization to yield the polymers displaying optical rotations and Cotton effects in the UV–vis absorption region of side groups distinct to monomers (3) and the corresponding model compounds such as (S)-6-propionyl-2,2′-bisalkoxy-1,1′-binaphthyl (4) and (S)-6-heptanoyl-2,2′-bisalkoxy-1,1′-binaphthyl (5), implying the formation of main-chain chirality, most probable helicity. Their helical conformations were quite stable as revealed by the almost unchanged chiroptical properties measured at different temperatures.