Work

Synthesis of Single‐Handed Helical Spiro‐Conjugated Ladder Polymers through Quantitative and Chemoselective Cyclizations**

Year: 2021

Type: article

Abstract: We report the unprecedented synthesis of one-handed helical spiro-conjugated ladder polymers with well-defined primary and secondary structures, in which the spiro-linked dibenzo[a,h]anthracene fluorophores are arranged in a one-handed twisting direction, through quantitative and chemoselective acid-promoted intramolecular cyclizations of random-coil precursor polymers composed of chiral 1,1'-spirobiindane and achiral bis[2-(4-alkoxyphenyl)ethynyl]phenylene units. Intense circular dichroism (CD) and circularly polarized luminescence (CPL) were observed, whereas the precursor polymers exhibited negligible CD and CPL activities. The introduction of 2,6-dimethyl substituents on the 4-alkoxyphenylethynyl pendants is of key importance for this simple, quantitative, and chemoselective cyclization. This strategy is applicable to the defect-free precise synthesis of other varieties of fully π-conjugated molecules and coplanar ladder polymers that have not been achieved before.

Source: Angewandte Chemie International Edition

DOI: 10.1002/anie.202102885

Authors: Wei Zheng, Tomoyuki Ikai, Eiji Yashima

Institution: Nagoya University

Language: English

Topic: Synthesis and Properties of Aromatic Compounds

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funder: Japan Society for the Promotion of Science

Awards: Development of Ultimate Functions Based on Helical Polymers with Helicity Memory, Synthesis of Chiral Supramolecules Driven by Self-Assembly of Ladder Molecules and Their Application