Synthesis of Interlocked and Non‐Interlocked Deca(para‐phenylene) Derivatives by Ni‐mediated Biaryl Coupling

• Published in: Chemistry : a European journal 2024-03, Vol.30 (16), p.e202304309-n/a
• Main Authors: Ohta, Misuzu, Okuda, Ayano, Hosoya, Shoichi, Yoshigoe, Yusuke, Saito, Shinichi
• Format: Article
• Language: English
• Subjects: C−C coupling; nickel; oligo(para-phenylene); Rotaxanes; Solubility; Synthesis
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202304309

Oligo(para‐phenylene) (PPn) is a compound composed of directly connected 1,4‐phenylene moieties. The synthesis of PPn composed of six or more phenylene moieties with no substituent at the internal phenylene moiety has been challenging because of its low solubility. Herein we synthesized oligo(para‐phenylene)[2]rotaxanes, including a deca(para‐phenylene)[2]rotaxane, with a defined number of phenylene moieties. Biaryl coupling of iodoarenes mediated by macrocyclic dibenzodihydrophenanthroline‐Ni complex was utilized for the first time to synthesize the [2]rotaxanes. Compared to the non‐interlocked deca(para‐phenylene), the deca(para‐phenylene)[2]rotaxane showed higher solubility. The properties of the oligo(para‐phenylene)[2]rotaxanes and non‐interlocked oligo(para‐phenylene)s were analyzed by spectroscopic methods. [2]Rotaxane with deca(para‐phenylene) structure was synthesized in high yield under mild conditions by biaryl coupling mediated by a macrocyclic nickel complex. Deca(para‐phenylene)[2]rotaxane was readily soluble, and the optical properties of the compounds were examined in solution.