Synthesis and Properties of Optically Active [7]Helicene-Fused Oxanorbornene Polymers by Ring-Opening Metathesis

Optically active [7]­helicene-fused oxanorbornene polymers poly-1 were synthesized by ring-opening-metathesis polymerization (ROMP) of monomer 2, which was easily accessed by [4 + 2] cycloaddition of in situ-generated [7]­helicenyl aryne and furan. The optical resolution of rac-2 using a chiral stationary phase afforded optically active (P)-2 and (M)-2. Of the various Grubbs catalysts tested, the first-generation one was found to be optimal for this ROMP. The chiroptical properties of the polymers were studied using circular dichroism and circularly polarized luminescence.