Zr-promoted cyclization of diynes bearing C2-chirality:: synthesis and properties of new chiral conjugated molecules

Conjugated oligomers bearing 4,5,6,7-tetrahydro-5S,6S-dioctyloxybenzothiophene as a central linkage were synthesized by Negishi's reagent (n-Bu2ZrCp2) promoted intramolecular cyclization of a diyne and subsequent Suzuki coupling reactions. The chirality in the central linkage originated from tartaric acid, which induced the conjugated backbone of oligomers to exhibit interesting optical activity. (C) Elsevier Science Ltd. All rights reserved.