Advertisement

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Synthesis

Pentacenes Exhibit Unsymmetrical Side

Synthetic strategy broadens the chemical repertoire of this electronically useful class of compounds

by Elizabeth K. Wilson
November 1, 2010 | A version of this story appeared in Volume 88, Issue 44

A synthetic strategy that produces previously rare unsymmetrical pentacene derivatives has been developed, broadening the chemical repertoire of this industrially useful class of compounds (Org. Lett., DOI: 10.1021/ol102349r). Pentacenes, a linear framework of five benzene rings, can be used to make a host of electronic materials, from organic semiconductors to solar cells. Until now, pentacenes have typically been symmetrical, and only rarely have examples with substituents in the pentacene framework’s 5-position been reported. Yoichiro Kuninobu, Kazuhiko Takai, and colleagues at Okayama University, in Japan, began by making unsymmetrical isobenzofurans via a rhenium-catalyzed C–H bond transformation from aromatic ketimines and aldehydes. They followed that step with a Diels-Alder reaction between the isobenzofurans and 1,4-anthraquinone. The reduced products yielded the unsymmetrical functionalized pentacenes. The team was able to attach alkoxy, trifluoromethyl, methoxycarbonyl, bromo, and thiophenyl functional groups to the 5-position. The researchers say that compared with other pentacenes these new derivatives are highly soluble in hexane, toluene, and tetrahydrofuran, which should ease processing in applications.

Article:

This article has been sent to the following recipient:

0 /1 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.