Twisted Polycyclic Arenes from Tetranaphthyldiphenylbenzenes by Controlling the Scholl Reaction with Substituents. Issue 51 (9th November 2016)

• Record Type: Journal Article
• Authors: Yang, Yong; Yuan, Luyan; Shan, Bowen; Liu, Zhifeng; Miao, Qian
• Is Part Of: Chemistry. Volume 22:Issue 51(2016)
• Page Start: 18620
• Page End: 18627
• Publication Date: 2016-11-09
• Subjects: arenes -- organic semiconductors -- oxidative cyclodehydrogenation -- polycycles -- regioselectivity; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201604649
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Herein, we report two new types of twisted polycyclic arenes (2 a, b and3 a, b ) with constitutionally isomeric π‐backbones, which are synthesized by controlling the Scholl reaction of 1, 2, 4, 5‐tetra(naphth‐2‐yl)‐3, 6‐diphenylbenzene (1 ) with properly positioned electron‐donating substituents. With a polycyclic backbone containing two [5]helicene and four [4]helicene moieties, 2 a andb are new members of multiple helicenes with interesting stereochemistries. The as‐synthesized2 a andb are the twisted isomers, and thermal isomerization of twisted‐2 b results in anti ‐2 b, a more stable stereoisomer. Both twisted‐ and anti ‐2 b have been fully characterized, and the thermal isomerization of twisted‐2 b has been studied with 1 H NMR spectroscopy and DFT calculations. Compounds3 a andb are new members of twistacenes, the benzannulated pentacene backbone of which exhibits an end‐to‐end twist as found from the crystal structure. Twisted‐ and anti ‐2 b are also found to function as p‐type semiconductors in solution‐processed thin film transistors, whereas the thin films of3 b appear insulating presumably due to the lack of π–π interactions. Abstract : Let's twist again : Two new types of twisted polycyclic arenes with constitutionally isomeric π‐backbones are synthesized by controlling the Scholl reaction of 1, 2, 4, 5‐tetra(naphth‐2‐yl)‐3, 6‐diphenylbenzene with properly positioned electron‐donating substituents (see scheme).