The study of chiral conjugated polymers

Structurally Rigid and Optically Active Dendrimers

“…In the presence of ( S )- 10 (5 mol %) in toluene solution, a 98.6% conversion of benzaldehyde is observed in 24 h at room temperature. However, only 37% conversion is observed under the same condition when BINOL is used 6h. Both the enantioselectivities of ( S )- 10 19 and BINOL 6h are very low.…”

“…Previously we have shown that the conditions for the coupling of aryl bromides with alkynes (at ∼ 70 °C) do not racemize the binaphthyl structure. 6c,l Therefore, we expect dendrimers ( S )- 8 , ( S )- 9 , ( S )- 10 , and ( R )- 10 to retain their enantiomeric purity. This is supported by a HPLC analysis of 10 using a Chiralcel-OD column.…”

“…The increased catalytic activity of ( S )- 10 over BINOL indicates that the zinc complex generated from the reaction of ( S )- 10 with diethylzinc may have much higher Lewis acidity than the zinc complex generated from BINOL. The zinc complex formed from the reaction of BINOL with diethylzinc is found to likely exist as aggregates in solution through intermolecular Zn−O−Zn bonds which should greatly reduce the Lewis acidity of the zinc center 6h. We expect that such aggregate cannot form in the case of ( S )- 10 due to the large dendritic arms as indicated by Figure .…”

Synthesis and Redox-Driven Chiroptically Switching Properties of Viologen-Containing Optically Active Polymer with Main-Chain Axial Chirality

“…1,1′-Binaphthyl (BN)-based chiral conjugated polymers have been extensively studied by Pu et al for their potential use in asymmetric synthesis and chiral recognition. Most polymers in their study exhibited secondary chirality (e.g., major groove with cisoid conformation) due to the rigid main-chain structure as well as the strong twisting power of BN at both the 2,2′ and the 6,6′ positions.…”

Functionalized Major-Groove and Minor-Groove Chiral Polybinaphthyls: Application in the Asymmetric Reaction of Aldehydes with Diethylzinc

“…14 nm blue-shift from the major-groove polymer to the minor-groove polymer, indicating a reduced effective conjugation in ( R )- 17 . According to our earlier work on the binaphthyl-based chiral conjugated polymers, the conjugation of these materials is determined by their repeat units and there is no extended conjugation along the polymer chain …”