Pyrenes, Peropyrenes, and Teropyrenes: Synthesis, Structures, and Photophysical Properties. Issue 35 (26th July 2016)

• Record Type: Journal Article
• Authors: Yang, Wenlong; Monteiro, Jorge H. S. K.; de Bettencourt‐Dias, Ana; Catalano, Vincent J.; Chalifoux, Wesley A.
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 35(2016)
• Page Start: 10427
• Page End: 10430
• Publication Date: 2016-07-26
• Subjects: alkynes -- annulations -- arenes -- Brønsted acid -- macrocycles; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201604741
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The design of a relatively simple and efficient method to extend the π‐conjugation of readily available aromatics in one‐dimension is of significant value. In this paper, pyrenes, peropyrenes, and teropyrenes were synthesized through a double or quadruple benzannulation reaction of alkynes promoted by Brønsted acid. This novel method does not involve cyclodehydrogenation (oxidative aryl–aryl coupling) to arrive at the newly incorporated large arene moieties. All of the target compounds were synthesized in moderate to good yields and were fully characterized with the structures unambiguously confirmed by X‐ray crystallography. As expected, photophysical characterization clearly shows increasing red‐shifts as a function of extended conjugation within the fused ring systems. Abstract : Pyrenes with a twist : The synthesis of soluble pyrenes, peropyrenes, and teropyrenes using a two‐ and fourfold alkyne benzannulation reaction promoted by Brønsted acid is reported. The compounds show an expected red shift in absorbance and emission as a function of conjugation length with quantum yields of up to 62 %. X‐ray crystallographic analysis of these polycyclic aromatic hydrocarbons shows significant twisting of the aromatic core, thus demonstrating how flexible nanographenes can be.